Contraluminal Organic Anion and Cation Transport in the Proximal Renal Tubule: V

View metadata, citation and similar papers at core.ac.uk brought to you by CORE

provided by Elsevier - Publisher Connector

Kidney International, Vol. 36 (1989), pp. 78—88

Contraluminal organic anion and cation transport in the proximal renal tubule: V. Interaction with sulfamoyl- and phenoxy diuretics, and with /3-lactam antibiotics

KARL J. ULLRICH, GERHARD RUMRICH, and SONJA KLOSS

Max-Planck-Institut für Biophysik, Kennedyallee 70, D-6000Frankfurt/Main70, Federal Republic of Germany

Contraluminal organic anion and cation transport in the proximal renal An important function of the kidney is the secretion of drugs tubule: V. Interaction with suifamoyl- and phenoxy diuretics, and with and xenobiotics and of their metabolites. The magnitude of 13-lactam antibiotics. In order to study the interaction of sulfamoyl- and renal excretion has an important impact on the drug's half-life phenoxy diuretics as well as of /3-lactam antibiotics with the contraluminal anion and cation transport systems the inhibitory potency ofand, thereby, on systemic drug levels. An impaired excretion these substances against the influx of 3H-para-aminohippurate, '4C- may cause drug or xenobiotic accumulation in the body and succinate, 35S-sulfate and 3H-N'-methylnicotinamide into cortical tubu- give rise to toxic effects. An impairment of excretion can occur lar cells have been determined. 1.) 2-, 3- and 4-sulfamoylbenzoatethrough lesions of tubule segments responsible for drug secre- inhibit contraluminal PAH influx. N-dipropyl substitution to yieldtion or through competition between two drugs or xenobiotics probenecid or ring-substitution to yield furosemide and piretanide augment the inhibitory potency. However, hydrochlorothiazide and for a common, rate-limiting secretory transport system in acetazolamide exert only a moderate inhibitory potency. Succinatetubule cells. To better understand and even to avoid unwanted transport was inhibited by furosemide only. Sulfate transport wasdrug interference, it is mandatory to elucidate the molecular inhibited by furosemide and 3-sulfamoyl-4-phenoxybenzoate as well as mechanisms which are responsible for drug excretion in the by probenecid, piretanide, hydrochlorothiazide and acetazolamide. 2.)kidney. The goal of the present study is, therefore, to determine Phenoxyacetate, -propionate, and -butyrate exert increasing inhibitionthe transport systems that take up sulfamoyl- and phenoxy against PAH transport. The weed-killers 2,4-dichloro-, and 2,4,5-diuretics as well as /3-lactam antibiotics from the blood into the trichlorophenoxyacetate (2,4 D and 2,4,5 T) had a similar inhibitory potency, while ethacrynic acid showed a lower and the uricosuricproximal tubule cell. tienilic acid a higher inhibitory potency. None of the compounds of this Drugs and xenobiotics are secreted in proximal tubules via group interact with contraluminal succinate transport, and only thetransport systems for organic anions and cations. In previous multiring-substituted compounds 2,4 D, 2,4,5 T, ethacrynic and tienilic experiments we have established the specificity requirements of acid interact slightly with the sulfate transporter. 3.) The monocarboxy-the transporters for p-aminohippurate, dicarboxylate and sul- lic penicillins benzylpenicillin and phenoxymethylpenicillin as well as fate located in the contraluminal membrane of proximal renal the dicarboxylic ticarcillin interact with the contraluminal PAH transtubular cells [reviewed in 1, 2]. The PAH transport system port. The aminopenicillin ampicillin had a lower, and apalcillin a higher inhibitory potency than monocarboxylic penicillin. Benzylpeniciliin interacts with hydrophobic molecules carrying one or two ionic showed small inhibition against succinate transport and ticarcillinnegative charges or at least two partially negative charges. The against sulfate transport, 4.) The monocarboxylic cephalosporine, 6315 dicarboxylate carrier accepts molecules with two negative S Shionogi, and the aminocephalosporines, cephalexin and cefadroxil, charges at a proper distance of 5 to 9 A. Finally, the sulfate showed an app. KIPAHasthe comparable penicillins. The zwitterions transporter interacts with molecules with neighboring electro- cephaloridine and cefpirome did not interact with the PAH transporter, but with the organic cation (NMN) transporter. Amongst the amino- negative charge accumulation. Many drugs and xenobiotics thiazol-containing compounds cefotaxime, ceftriaxone, and cefodizime, fulfill these requirements and are transported by renal proximal increasing interaction with the PAH transporter was seen dependent of tubules [reviewed in 3—5].Sincesome drugs are zwitterions and a second ionizable anionic group. Compounds with two ionizablemight be transported by anion as well as cation transport anionic groups (cefsulodin, ceftnaxone, cefodizime) exert also a small systems, we established, in addition to the anion transport inhibitory potency against sulfate transport. None of the cephalosporins tests, an organic cation transport test with [3H]-N'-methylnico- interacted with the dicarboxylate transporter, The interaction pattern oftinamide as substrate. The results of our studies show that the the tested compounds is in accordance with the specificity requirements for the contraluminal transporters depending on electrical charge and interaction of probenecid, of the diuretics furosemide, pireta- hydrophobicity. nide, hydrochlorothiazide, acetazolamide, ethacrynic and tie- linic acid, and of the f3-lactam antibiotics of the penicillin and cephalosporin type interact with the anion and cation transport systems in a predictable fashion. Received for publication October 20, 1988 and in revised form February 22, 1989 Methods Accepted for publication March 2, 1989 The experiments were performed in male Wistar rats © 1989 by the International Society of Nephrology (Winkelmann, Kirchborchen, FRG) of 200 to 250 g body 78 U/inch et a!:Contralumina! organic anion and Cation transport 79 weight, fed an Altromin standard diet and tap water. Thesource of the inhibitors used is indicated in Tables 1 and 2, animals were anaesthetized by injecting mactin (Byk-Gulden,where (a) =Aldrich-Chemie,Steinheim, FRG; (bw) = Konstanz, FRG), 120 to 150 mg/kg body weight, intraperitone-Beecham-Wulfing,Neuss, FRG; (c) =Ciba-Geigy,Wehr, FRG; ally and placed on a heated operating table with a thermostat(0 =FlukaGmbH, Neu-Ulm, FRG; (g) =Grunenthai,Stol- control set at 37°C. An incision was made in the left flank andberg, FRG; (h) =HoechstAG, Frankfurt/M, FRG; (hi) = the kidney separated from the surrounding fascia. The capsuleHoechstAG, Dr. H.-J. Lang, Frankfurt/M, FRG; (hr) = was stripped off. The kidney was immobilized in a plastic cupHoffmann-LaRoche, Grenzach-Wyhlen, FRG; (in) =ICN, on cotton wool and covered with paraffin oil heated to 37°C.Plainview, New York, USA; (I) =Lederle,MUnchen, FRG; The renal artery and vein were isolated from the ureter so that(msd) =Merck,Sharp Dohme, MUnchen, FRG; (s) Sigma = they could be clamped. The renal artery and vein were clampedDeisenhofen,FRG; (st) =Stadapharm,Bad Vilbel, FRG; (sh) for each measurement of the disappearance rate of the radiola-=ShionogiCo., Dr. Masuhisa Nakamura, Osaka, Japan; (th) = belied substances. The proximal convoluted tubules then col- Thomae,Biberach, FRG. lapsed because the luminal fluid was reabsorbed, while glomer- ular filtration ceased. Immediately thereafter, a thick superficial Results capillary was impaled by an oil-filled sampling pipette (tip Sulfamoyl compounds and diuretics diameter about 6 m) for sample collection. At a distance of 100 to 140 sm from this glass capillary another blood vessel was Benzenesulfonamide with only partial negative charges ex- punctured with a filling pipette (tip diameter about 8 pm).erts only a small inhibitory potency against contraluminal PAH Through the filling pipette a rapid injection of an isotonictransport (app. K1 PAR 1.95 mmoi/liter; Fig. 1, Table 1) [2]. solution containing different concentrations of radiolabelledHowever, if the benzene ring has in addition a carboxylic substances and inulin as extracellular space marker was made.group, the app. K1 drops about 10-fold: 2-suifamoyi-benzoate After 1 to 4 seconds, as checked by an acoustic signal, the testapp. K-pAR 0.27 mmol/liter, 3-sulfamoylbenzoate 0.18 mmol/ solution was withdrawn into the sampling pipette. liter, and 4-sulfamoylbenzoate 0.3 mmoL/liter. N-dipropyl sub- The experiments with '4C-succinate [6], 35S-sulfate [7], 3H-stitution of the latter compound which yields probenecid aug- para-aminohippurate [8] and 3H-N '-methylnicotinamide [9]ments the affinity toward the PAH transporter further, that is, were performed as described in the respective references. Theagain by a factor of about 10 (app. K'PAH 0.03 mmol/liter). If 3H-'4C and 35S-radioactivity of the test substances and that of3-sulfamoyl-benzoate is further ring-substituted with a chloro- the reference substance (3H- or '4C-inulin) were measured in aor phenoxy group, the app. KIPAR remains in this range Betamatik I Kontron scintillation counter with Picofluor 15(3-sulfamoyl-4-chlorobenzoate, app. KIPAH 0.05 mmoLlliter; (Packard, Frankfurt/Main, FRG) as scintillation fluid. Since the3-sulfamoyl-4-phenoxybenzoate, app. KIPAH 0.05 mmoi/liter). control values varied during the two-year time period in whichAlso a fourth substitute, a furylmethylamino group which yields the experiments were performed, the experimental data werethe diuretic furosemide or a pyrrolidine group, as in the case of appropriately corrected. the diuretic piretanide, does not change the affinity (furosemide The standard solution injected into the capillaries, for theapp. KIPAH 0.04 mmol/liter, piretanide app. KIPAH 0.07 mmoL1 35S-sulfate and 3H-para-aminohippurate experiments, con-liter). In contrast, the diuretic hydrochiorothiazide or the car- tained in mmol/liter: 150 Na, 4 K, 154 gluconate. In the '4C-bonic anhydrase inhibitor acetazolamide have a much lower succinate and 3H-N'-methylnicotinamide experiments the stan-affinity (hydrochlorothiazide app. KI,PAH 0.72, acetazolamide dard solution contained: 146 Nat, 4 K, 1.5 Ca2, 1 Mg2, 1301.3 mmol/liter). As the interaction with the contraiuminai dicar- C1, 25 HC03. All added substances replaced an equivalentboxylate transport concerns, only the doubly para-substituted amount of gluconate or chloride so that the osmolality remainedfurosemide (app. 5.1 mmol/liter) exerts a small inhibitory constant. The solutions were gassed with pure °2 in the sulfatepotency. and para-aminohippurate experiments, but with 95% N2, 5% Interaction with the contralurninal sulfate transporter was CO2 in the dicarboxylate and N '-methylnicotinamide experi-seen with probenecid (app. K50 7.3 mmol/liter), 3-sulfamoyl- ments. The pH was set to 7.4. Further specifications are givenphenoxybenzoate (app. K1 ,S042 —0.78mmol/liter), furosemide in the legends to the figures. (app. K15042— 0.87 mmol/liter), piretanide (app. K1so42— 2.9 The apparent K1-values (app. K1) were evaluated as describedmmol/liter), hydrochlorothiazide (app. K15042— 4.4 mmol/liter), in [6]. The apparent K. values were used as operational values,and acetazolamide (app. K15O42— 6.4 mmol/liter). since competitive inhibition is assumed, but not proven explic- itly. All values are given as means SEM. The applied method Phenoxy compounds (weed killers and diuretics) has its limits at K1504 > 25 mmollliter, > 10 mmol/liter, Increasing the phenoxy side chain from acetate through KINMN and K.PAH > 5 mmol/liter. K1 values closely belowpropionate to butyrate the app. K1 against the contraluminal and above these limits therefore show a rather large SEM. The PPAH transporter drops from 0.4 to 0.27 to 0.04 mmol/liter (Fig. values were calculated from an unpaired t-test. The specific2, Table 1). The di- and trichloro-ring-substituted phenoxyace- activities of the isotopic tracers used were as follows: 35SO42tates, 2,4-dichlorophenoxyacetate and 2,4,5-trichlorophenoxy- 1400 Ci/mmol; 3H-PAH 6.8 Ci/mmol; '4C-inulin 15 mCi/g andacetate, have a high affinity (app. K1 PAR 0.03 and 0.05 mmol/ 3H-inuiin 164 mCiIg; these isotopes were obtained from Du Pontliter). Interestingly, the affinity of the diuretic ethacrynic acid (NEN, Dreieich, FRG). '4C-succinate with a specific activity of(app. K1 PAR 0.12 mmol/liter) and that of the uricostatic diuretic Ill mCi/mmol was obtained from Amersham Buchier (Frank-tienilic acid (app. K1 PAR 0.01 mmol/liter) are different from furt/Main, FRG). 3H-N' methylnicotinamide (3 Ci/mmol) waseach other by a factor 10. No interaction of the phenoxy obtained from ICN-Biochemicals (Eschwege, FRG). Thecompounds with the contraluminal succinate transporter was 80 Ullrich et a!: Contralumina! organic anion and cation transport

Table 1. Effect of benzenesulfamoyl and phenoxyacetate analogs on contraluminal influx of 35S-sulfate (4s), 3H-para-aminohippurate (2s), and '4C-succinate (is) into cortical renal tubular cells Para-amino-hippurate Succinate Sulfate K. K1 K1 Substances added m c(%±sE) (mM±sE) m c(%±sE) (mM±sE) ma c(%+sE) (mM±SE) Control 46.6 0.9 65.3 1.1 47.0 0.9 Benzenesuifonamide (t) 10 34.5 2.0 1.9 1.0 10 72.9 1.4 >10 5 43.8 1.8 >25 2-Sulfamoylbenzoate (h) 10 10.7 2.2 0.27 0.09 10 68.5 3.8 >10 5 43.0 3.4 >25 (saccharine) 3-Sulfamoylbenzoate (hi) 10 7.4 1.8 0.18 0.05 10 73.0 3.5 >10 5 43.7 2.0 >25 4-Sulfamoylbenzoate (a) 10 11.2 2.2 0.30.09 10 65.4 2.0 >10 5 48.0 1.0 >25 Probenecid (msd) 1 11.2 2.5 0.03 0.005 10 63.5 2.5 >10 50 18.2 2.6 7.9 2.2 5 39.4 2.2 7.3 10.4 3-Sutfamoyl-4-chloro- 1 17.9 2.6 0.05 0.01 10 61.2 3.7 10 5 42.4 3.9 >25 benzoate (hi) Furosemide (h) 10 6.0 3.5 0.14 0.02 10 48.9 3.2 5.1 8.9 5 19.0 3.4 0.87 0.3 1 14.2 3.1 0.04 0.01 3-Sulfamoyl-4-phenoxy- 1 17.3 2.9 0.05 0.01 10 62.0 3.1 >10 5 18.0 4.0 0.78 0.23 benzoate (hi) Piretanide (h) 10 0.5 1.9 0.01 0.001 10 67.3 2.1 >10 5 32.5 2.9 2.9 1.9 1 20.6 2.7 0.07 0.02 Hydrochiorothiazide (s) 10 21.5 1.9 0.72 0.19 10 58.9 2.1 >10 5 36.3 2.9 4.4 4.3 Acetazolamide (1) 10 29.3 1.7 1.3 0.47 10 60.3 3.7 >10 5 38.7 1.4 6.4 7.7 Phenoxyacetate (f) 10 20.2 1.4 0.65 0.17 10 70.6 3.1 >10 5 48.6 2.0 >25 1 41.6 3.8 0.4 0.51 Phenoxypropionate (in) 10 10.7 1.7 0.27 0.05 10 69.6 3.4 >10 5 50.3 2.4 >25 4-Phenoxybutyrate (t) 10 2.6 1.1 0.05 0.01 10 66.0 2.8 >10 5 48.3 3.1 >25 0.5 20.4 2.8 0.03 0.01 2,4-Dichlorophenoxy- 1 10.6 3.0 0.03 0.01 10 68.8 2.8 >10 5 41.0 2.7 10.4 21.3 acetate (a) 2,4,5-Trichlorophenoxy- 1 17.2 2.9 0.05 0.01 10 63.6 4.3 >10 5 35.9 2.0 4.2 3.7 acetate (a) Ethacrynic acid (msd) 1 27.9 2.0 0.12 0.04 10 67.5 2.6 >10 5 36.7 3.1 4.7 4.8 Tienilic acid (h) 1 5.7 2.3 0.01 0.002 10 60.8 3.7 >10 5 31.92.2 2.7 1.6 The starting concentration in the capillary perfusate was for 3H-para-aminohippurate 0.1,for '4C-succinate0.15, and for 35S-sulfate 0.01 mmol/liter. The first column indicates the compounds tested and their source (Methods), the 2nd, 5th and 8th column their concentration. The 3rd, 6th and 9th column indicate the percent decrease in contraluminal concentration relative to inulin during the respective contact time sri. The 4th, 7th and 10th column give the apparent K1±SE values in m calculated by a computer program according to refs. 6, 10 and 11.

observed. A small interaction with the contraluminal sulfate Cephalosporins transporter was, however, seen with all 2- and 3-fold substituted phenoxyacetates: 2,4 dichlorophenoxyacetate, app. The aminocephalosporin compound cephalexin (app. KIPAH K1s042— 10.4; 2,4,5-trichlorophenoxyacetate, 4.2; ethacrynic2.3 mmoi/iiter), which has the same structural formula as acid, 4.7, and tienilic acid, 2.7 mmol/liter. ampicillin except that the five-membered thiazolidin ring of the penicillins is extended to the six-membered dihydrothiazin ring Penicillins of the cephalosporins, has also the same inhibitory potency The one carboxylic group bearing penicillins benzylpenicillinagainst contraluminal PAH transport (Fig. 4, Table 2). The (penicillin G) and phenoxymethylpenicillin (penicillin V) exert aincorporation of an additional OH-group to yield cefadroxil moderate inhibitory potency against the contraluminal PAH-(app. KIPAH 3.0 mmol/liter) does not change the affinity. The transporter (app. KIPAH 0.81 and 0.7 mmollliter, respectively;monocarboxylic cephalosporin compound 6315 S Shionogi Fig. 3, Table 2). Benzylpenicillin with an additional amino(app. KIPAH of 0.94 mmol/liter) exerted the same affinity as the group to yield ampicillin has a much lower inhibitory potencymonocarboxylic penicillins. Monocarboxylic cephalosporins (app. KIPAR 2.5 mmol/liter). Interestingly, the apposition of awith an aminothiazol side group, such as cefotaxime, has a NH-CO-linked hydroxy-naphthyridin group to ampicillin toK,PAH of 3.1 mmol/liter, those with an ionizable enol group, yield apalcillin gives a very high inhibitory potency (app.that is, ceftriaxone, an app. KIPAH of 1.5 mmot/liter, and those K1PAH 0.02 mmoL/liter). The dicarboxylic penicillin ticarcillinwith a second carboxylic group, that is, cefodizime, an app. with an apparent KIPAH of 0.84 mmol/liter has a potency likeKIPAH of 0.22 mmol/liter. Monocarboxylic cephalosporins with penicillin 0 and V. Among the five penicillins tested, benzyi-a positively charged pyridin group do not interact with the PAH penicillin showed a small inhibitory potency against dicarboxy-transporter. However, when the net charge becomes negative late transport (app. K1 15.8 mmollliter) and tricarcillin againstby addition of a second anionic sulfonate group (cefsulodin app. sulfate transport (app. K1 8.2 mmol/liter), but none againstK1 PAR 1.9 mmol/iiter) a small interaction with the PAH trans- N1-methylnicotinamide transport. porter is seen. Among the cephalosporins tested, only the U/inch et al: Contraluminal organic anion and cation transport 81

Table 2. Effect of penicillins and cephalosporins on contraluminal influx of '4C-succinate (Is), 3H-para-aminohippurate (2s), 35S-sulfate (4s) and 3H-N'-methylnicotinamide (4s) into cortical renal tubular cells N '-methyl-nicotinamide Para-amino-hippurate Succinate Sulfate C1 K, K, K, K, Substances addedmc(%±sE) (mM±sE) msi c(%±sE) (mM±sE) msic(%±sE) (mM±sE) mric(%±sE)(mM±sE) Control 46.6 0.9 65.3 1.1 47.0 0.9 Benzylpenicillin (s) 10 23.1 2.70.81 0.2410 56.7 2.415.8 6.9 550.1 3.3 >25 535.1 3.2 >5 Phenoxymethyl- 10 21.1 2.6 0.7 0.1810 61.3 4.8 >10 546.1 1.7 >25 542.0 2.4 >5 penicillin (s) Ampicillin (st) 10 37.4 2.1 2.5 1.5510 60.8 3.6 >10 543.7 2.4 >25 534.0 3.2 >5 Apalcillin (th) 0.132.6 3.80.02 0.0110 63.8 2.1 >10 544.9 2.6 >25 536.0 1.4 >5 Ticarcjllin (bw) 10 23.5 2.1 0.84 0.2410 65.7 1.6 >10 540.0 2.38.2 13.2 539.2 1.6 >5 Cephaloridine (s) 25 41.9 2.9 >5 10 62.64.2 >10 549.8 4.0 >25 523.2 2.52.1 0.8 10 45.6 3.2 >5 Cefpirome 10 50.0 3.2 >5 10 67.0 1.7 >10 547.8 3.2 >25 514.6 2.60.9 0.3 (HR 810) (h) Cefsulodin (g) 10 34.4 2.2 1.9 1.0 10 64.8 1.8 >10 539.3 2.67.2 10.0 534.8 2.7 >5 Cefotaxime (h) 25 28.7 2.2 3.1 1.1 10 63.3 4.1 >10 546.5 1.9 >25 531.8 3.5 >5 10 47.5 1.9 >5 2 46.2 3.2 2.2 5.5 Ceftriaxone (hr) 10 29.7 3.2 1.5 0.7 10 60.7 2.4 >10 541.7 2.412.7 3.0 540.2 2.8 >5 Cefodizime 10 8.8 1.6 0.22 0.0610 62.6 2.3 >10 5 36.7 1.6 4.7 4.4 540.8 1.6 >5 (HR 221) (h) 6315 5 Shionogi 10 25.1 2.00.94 0.2810 67.4 2.6 >10 548.1 1.3 >25 533.0 3.9 >5 (sh) Cephalexin (h) 10 36.2 2.0 2.3 1.2510 68.8 2.6 >10 549.9 3.0 >25 539.7 2.5 >5 Cefadroxil (c) 10 39.0 2.6 3.0 2.2 10 66.0 2.1 >10 543.7 1.6 >25 533.8 1.9 >5 The starting concentration in the capillary perfusate was for 3H-para-aminohippurate 0.1 mmol/liter, for '4C-succinate 0.15, for 35S-sulfate 0.01, and for 3H-N'-methylnicotinamide 0.1 mmol/Iiter. The first column indicates the compounds tested and their source (Methods), the 2nd, 5th, 8th and 11th column their concentration. The 3rd, 6th, 9th and 12th column indicate the percent decrease in contraluminal concentration relative to inulin during the respective contact time SE. The4th, 7th, 10th and 13th column give the apparent K1±SE values in m calculated by a computer program according to refs. 6, 10 and 72. zwitterionic cephaloridine (app. KINMN 3.7 rmol/liter) and Sulfonamides cefpirome (app. KNMN 1.3 mmol/liter) interact with the contraluminal organic cation transport. Interestingly, all three Benzenesulfonamide exerts an inhibitory potency against compounds which had two ionizable anionic groups interactedcontraluminal PAH transport with a KIPAH of 1.9 mmol/liter, with the sulfate transport system (cefsulodin app. K15042— 7.2which is in the same range as that of the readily ionized mmollliter; ceftriaxone app. K1so42— 12.7 mmol/liter; and cefo-benzenecarboxylate (benzoate, app. KpAH 1.5 mmol/liter) or dizime app. Kso42— 4.7 mmol/liter). benzenesulfonate (app. KIPAH1.9mmollliter) [2]. Thus, it behaves like a hydrophobic anion, although the PKa value of the Discussion SO2 NH2 group ranges between 9.4 and 10.3; that is, it behaves A semiquantitative structure interaction relationship [11, 12]like a very weak acid and thus is similar to that of phenols [2]. can now be established for contraluminal organic anion trans-As expected from their structural formulae hydrochlorothiazide port processes, because enough basic information is available.(app. KIPAH 0.72 mmol/liter) and acetazolamide (app. KpAfl This study attempts to relate the chemical structure of drugs1.3 mmol/liter) exert similar inhibitory potencies. In concert and xenobiotics to their interaction with the organic anion andwith a C00-group, however, the sulfamoyl group behaves cation transport systems at the contraluminal cell side of thelike an electronegative partially-charged group such as Cl, proximal renal tubule. So far, three different anion transportHCO, NO2, or a second negative ionic charge, which both systems have been identified [1, 111: for hydrophobic anionsaugment the affinity toward the PAH transporter considerably (PAH), for dicarboxylates and for sulfate. The PAH transport[2]. Furthermore, if an additional hydrophobic moiety (N- system interacts with hydrophobic molecules carrying one ordipropyl) is introduced into the 4-sulfamoylbenzoate molecule two negative ionic charges or two or more negative partialto yield probenecid or a hydrophobic chloro-, phenoxy- or charges. In the case of benzoates and phenolates log KIPAH ispyrryl group attached to the ring of the 3-sulfamoylbenzoate to proportional to the log PKa values [2]. The dicarboxylateyield the diuretics SD 14108 (that is, 3-sulfamoyl-4-chloro- transporter requires two electronegative ionic charges at 5 to 9benzoate), furosemide and piretanide, a high affinity toward the A distance [11], where one of the two charges may be a partialPAH transporter was seen (app. KIPAH 0.05 mmol/liter). charge. The sulfate transporter interacts with molecules whichFurthermore, these groups are electron attracting, which is have neighboring electronegative charge accumulation. In con-electronegative. Thus, the substances mentioned qualitatively trast to the anion transport systems, there no evidence existsfollow the rules found for interaction with the PAH transporter for the presence of more than one contraluminal organic cation[1, 2]. transport system. It is more difficult to tell why furosemide interacts with the 82 U/Inch et a!: Contraluminal organic anion and cation transport

Paraaminohippurate Succinate Sulfate U) U) U) F-. 0 0 oq o - II N 0U) U) U) 0N. C) 0 0 -: o o o0 0 0 U) 0 0 0 0 U) 0 0 0 U) 0 0 0 I I ______I I Control

sulfonamide H2NO2S

2-Sulfamoyl COOH I j.1 benzoate T I I SO2NH2

3-Sulfamoyl III 1. A I benzoate H2NO2S_Jc:LCOOH

4-S1farnOy H2NO2S —4-- OOH + f

Probenecid (CH3CH2CH2)2N502 —4,--- COOH +

3Sulfamoyl- Cl 4-chioro TtTh1 J-4 Ii.. benzoate H2NO2S2 COOH II 3-Sulfamoyl- 4-chioro 6-(2-furyl- CL NH—CH2—'Ui I,j I methylamino) 0 i T benzoate COOH [furosemide) H2NO2S I

IL benzoate:=vl. O0.io I H2N02S"C0OH II 3-Sulfamoyl- I 5-pyrrotdine I + [piretanide] H2NO2S COOH

Hydrochiorothiazide if + H22NOSOISH 02

Acetazolamide I H2NO2S S NHCOCH3 I (TI

Fig.1. Effect of sulfamoylbenzoate and analogues on contraluminal influx of 3H-para-aminohippurate, '4C-succinate and 35S-sulfate into renal cortical cells. The respective values of contact time, starting concentration, control decrease of contraluminal test-concentration during the indicated contact time, and concentration of the added competitors were: in the 3H-para-aminohippurate series: 2 seconds, 0.1 mmol/liter, 0.047 mmol/liter, 10 mmol/liter, solid bar, 1 mmol/liter dotted bar; in the 14C-succinate series: 1 second, 0.15 mmollliter, 0.098 mmollliter, 10 mmol/liter; in the 35S-sulfate series: 4 seconds, 0.01 mmol/liter, 0.0047 mmol/Iiter, 5 mmol/liter. Each bar represents the mean SCM of 7 to 18 samples from 2 to 4 animals. dicarboxylate transporter and other sulfamoyl compounds do proper distance. In contrast, most of the tested substances not, although they fulfill the requirement for interaction, that is,interact with the sulfate transporter although some of them they have one anionic plus one electronegative group at a (probenecid and acetazolamide) do not fulfill the requirement of Ui/rich et ai: Contraluminal organic anion and cation transport 83

Paraam inohiixurate Succinate Sulfate U) U) U) N 0 '- 0 0 .,- 0 0 0 o II ,.)_ U) U) N 1 N 0 0 •-. .- 0 q q 0 -: o 0 0 0 0 E o U) 0 0 00 U) o 0 00 U) 0 0 I I — — I

Control I I T T

Phenoxy- I ti acetate —O—CH2COOH F+ 1

Phenoxy- 2I2COOH propionate 4 Ii

Phenoxy- II butyrate —O—(CH)3COOH + If

2,4-Dichloro- Cl —4---O— CH2COOH + phenoxyacetate IT

I Cl I I 2,4,5-Trichioro- II phenoxyacetate Cl —--O— CH2COOH T Cl I

Ethacrynic H5C2'.., acid + + H2C Cl Cl

Tienil Ic II acid 1' I-I 1jJ_COo_CH2COOR + I Cl Cl I

Fig.2. Effect of phenoxyacetate and analogues on contraluminal influx of 3H-para-aminohippurate, '4C-succinare and 35S-sulfate into renal cortical cells. Experimental conditions are in Fig. I legend. the negative group accumulation. This leads us to suppose thatprobenecid might be transported by a "subsystem for organic the SO2NH2 group has preference toward the sulfate trans-anion transport". Although the interaction of probenecid with porter as compared with other electronegative groups. the sulfate transport system which we observed is rather weak The present study shows that almost all pharmacologically(Fig. I, Table 1), such a possibility indeed exists. Inhibition by important benzenesulfonamides interact with more than oneprobenecid and/or PAH was also seen for renal transport of contraluminal anion transport system: acetazolamide [23, 24], hydrochlorothiazide [13, 25, 26], and indirectly via inhibition of diuresis by furosemide [27—30] and 1.) The carbonic anhydrase inhibitor acetazolamide interactspiretanide [31]. Since some authors felt that acetazolamide as with the PAH and sulfate transporter. well as hydrochlorothiazide excretion by the kidney is rather 2.) The diuretics piretanide, furosemide and hydrochlorothia-low, Maren [32] as well as Peters and Roch-Ramel [33] dis- zide interact also with the PAH and sulfate transporter. Incussed that besides secretion and non-ionic back diffusion, an addition furosemide also interacts with the dicarboxylate "element of active reabsorption" might be involved in overall transporter. renal handling of these substances. Our finding that acetazol- 3.) The "organic anion transport inhibitor" probenecid inter-amide as well as hydrochlorothiazide interact with two contra- acts with very high affinity with the PAH transporter,luminal anion transporters support such a suggestion, since the while its interaction with the sulfate transporter is rather probability of countertransport is given if two or more systems weak. are involved. In fact, however, that interaction with all three Probenecid and congeners as well as PAH exert mutualcontraluminal anion transporters does not necessarily diminish inhibition of their renal clearances [14—17], of accumulation inrenal clearance was seen with furosemide, where with protein- kidney cortical slices [18—201, and of uptake into basolateralfree renal perfusion its clearance was as high as that of membrane vesicles [21, 221. Since probenecid accumulation inpara-aminohippurate [34]. Net transport of a substance across renal slices was inhibited by PAH to a relatively smaller extentthe proximal tubular cell layer depends on concentration, than expected, Sheik et al [5, 20] discussed the possibility thataffinity and driving force of that substance for the different 84 U/Inch et al: Contraluminalorganicanion and cation transport

N1-methyt-nicotin- Paraaminohippurate Succinate Sulfate amide U, U) 0U) 0N 0 IS) 0 0 o oR N IC) 0N 0r) 0 N q0 fl 0 ddo0o° is 0q 00 0000 0 U 0 00 ____ I I I ______Control IF

HH CH3 Benzyl penicillin -CHCONHjt}. + +

H H CH Phenoxymethyl penicillin (j-OCH2CONf-Sj.N CH, IF o co2 HH CH3 Ampicillin Q..CHCONH}.CH + NH2 II OH I-I H CH3 CONH.C-CON Apalcillin CH3 LJLNJ a- o CO2 t H H CH3 Ticarcillin I-]-CHCON CO2FCO2 Fig. 3. Effect of penici/lins on contraluminal influx of 3H-para-aminohippurate, '4C-succinate, 35S-sulfate and 3H-N'-methylnicotinamide into renal cortical cells. Experimental conditions are in Fig. I legend. For 3H-N'-methylnicotinamide contact time was 4 seconds; starting NMN concentration 0.1 mmollliter, control decrease of NMN during 4 seconds contact time 0.036 mmol/liter and concentration of the added competitors 5 mmol/liter. Cor. means that the inhibition, seen with other concentrations than 10 mmol/liter (Table 2), is recalculated for 10 mmollliter.

transport system at the contraluminal and luminal cell side withaminohippurate inhibits the transport of phenoxyacetate [35], 2, which the substance interacts. Even if we knew the complete4-dichioro- or 2,4,5-trichlorophenoxyacetate [36—38], etha- transport characteristic of a substance with all transporterscrynic acid [39], and tienilic acid [40—42]. Similar to the sulfa- involved, the mutual interaction with other substrates makes amoyl diuretics, probenecid diminishes the diuretic effect of prediction of net transport rates almost impossible. ethacrynic acid [43]. Thus, a common transport mechanism for PAH, probenecid and phenoxycarboxylates is evident. Unfor- Phenoxybenzoate compounds (weed killers and diuretics) tunately, the high serum protein binding of polysubstituted The affinity of these compounds against the contraluminalphenoxy compounds and their non-ionic back diffusion [42, 43] PAH transporter increases with their hydrophobicity fromprecludes a quantitative comparison of clearance data with our phenoxyacetate (app. KIPAR 0.4 mmol/liter) to phenoxybuty-transport data. Elimination from the blood is low [36, 44] and rate (app. KIPAH 0.05 mmollliter). Similarly, the introduction ofpartially due to biotransformation and excretion by the liver chloro-groups into phenoxyacetate as well as the introduction[43, 45]. Furthermore, it is premature to speculate about of the methylenebutyryl or thienylcarbonyl group increasestransport of these compounds through the contraluminal sulfate their hydrophobicity. All these compounds exerted a hightransporter and luminal anion transporters during overall tubu- inhibitory potency against the PAH transporter. Since the PKalar secretion. values of the phenoxy compounds, which we tested, did not deviate very much from each other, the main determinant for Penicillins interaction seems to be the hydrophobicity. On the other hand, Already in the early forties it was seen that penicillin is steric effects as we have seen previously with the interaction ofexcreted by the kidney via the organic anion transport system cis and trans-cinnamate toward the PAH transporter [Fig. 9 in[reviewed in 5, 46]. Probenecid was even developed to retard ref. 2] cannot be excluded, especially with ethacrynic acid, therenal excretion of penicillin [47, 48] as was the case with PAH KIPAH of which is relatively high, and which has a double bond[49]. In man the clearance of unbound benzylpenicillin is as high in the side chain. as that of PAH [48, 50, 51].Theclearance of unbound ampicil- From our specificity pattern against the other two contralu-un, however, is only half the value [52]. Our data (Fig. 3, Table minal anion transport systems it is not surprising that none of2) show that the five penicillins tested interact with the contra- the compounds interacted with the succinate transporter, butluminal PAH transport system, although the affinity of the that the multi-ring-substituted compounds interacted to a smallmonocarboxylates benzylpenicillin and phenoxymethylpenicil- degree with the sulfate transporter. In whole organ or kidneyun as well as of the dicarboxylic ticarcillin is rather moderate. slice experiments the application of probenecid and/or para-The reason for this might be the moderate hydrophobicity of Ullrich et al: Contraluminal organic anion and cation transport 85

Paraaminohippurate Succinate Sulfate N1-methyl-nicotinamide to to U, N 0 0It, 0 0 0 0 U) U3 10 N r.. 0 N 0 0 0 o0 00 0 Oo 0 U,d oo do d toddo0 to0 do _1__ I I Ij_ I _3 I Control I 7

HH I I

I Cephaloridine [JCH2CONHLS - o N.)CH2N I + C02- I RH N CCONHj._fS Cefpriome H2r.JQJ1 (HR81O) 'OCR30—NCH2ico2- RH

Cefsulodin _CCONHr—S I C02- HH N C-CONHi---i Cefotaxime I H2NçT L_NJCH2OCOCH3 OCR, CO2 HR 0 N // N C-CONHH I Ceftriaxons H2NT LNCH2SO + 7 IT 'OCH3 co2- 1NH I CR3 RH N N CR3 Cefodizime C-CONHF- (HR221) H2NI[ LN)CH,SLçICH2CO2- I I "OCH, C02 I H,COH I F2CHSCH2CONHF-+° N—N II 63l5SShionogi NJCH2St.NN C02 CH,CHOH I HR

Cephalexin H R2 e'NCH, TI II CO2 I I I HR I i Cephadroxil HOc_CONHi(S HNH,OI NCRI Co2— I I Fig.4. Effect of cephalosporins on contraluminal influx of 3H-para-aminohippurate, '4C-succinate, 35S-sulfate and 3H-N'-methylnicotinamide into renal cortical cells. Experimental conditions see legend to Fig. 3. Cor. means that the inhibition, seen With other concentrations than 10 mmol/ liter (Table 2), is recalculated for 10 mmol/liter. these compounds (log P0 1.7, 2.0 [12] and 1.2, respectively).reduction of inhibitory potency. At the pH of our perfu sate only If, however, the hydrophobicity is very high as with apalcillinhalf of the added compound is in the form of an anion, the other (log P0 3.4),! the inhibitory potency toward the PAH transporthall is zwitter-ionic. Thus, the degree of interaction of the system increases considerably. In addition, this compoundtested penicillins with the PAH transport system could be shows high protein binding and excretion by the liver. In theexplained satisfactorily by the rules established recently [1, 2]. case of ampicillin (log P0 1.5) the electropositivity of the NH2-group with an PKa of 7.24 seems to be responsible for the Cephalosporins Among the J3-lactam antibiotics a much larger variety of The log P of undissociated ticarcillin and apalcillin were calcu-cephalosporins is available compared with penicillins [53, 54]. lated by Dr. G. Gorlik,HoechstAG, Frankfurt, using the programSome of the cephalosporins are zwitterions [55] which are CLOGP 3.4. The ig P0 of undissociated apalcillin was also determined transported by anion as well as cation transport systems across experimentally by us. luminal and contraluminal cell membranes [56—59]. Further- 86 UI/rich et a!: Contralumina! organic anion and cation transport more, at the luminal cell side, transport of /3-lactam antibioticsof '9F-NMR-measurements with fluorinated test substrates [64] share the system for H-dipeptide cotransport [60—62]. Thus,and by studying the interaction with the different cephalospo- the overall behavior of those substances in transtubular trans-rins. Using this approach the evaluation of competitive inhibi- port become rather complicated and almost unpredictable. Onetion and/or trans-stimulative acceleration of cephalosporins and step toward better understanding is to select examples fromother substrates at either cell side seems to be feasible [73]. each group of cephalosporins and to test their interaction with contraluminal anion and cation transport. As can be judged Conclusions from Figure 4 and Table 2, a clear correlation of structure and The excretion of a substance by the kidney comprises a) interaction could be seen: 1.) The zwitter-ionic cephaloridineglomerular filtration, b) additional proximal tubular net secre- and cefpirome interact with the organic cation (NMN) trans-tion or reabsorption, and c) possibly additional non-ionic back port system only, but not with the three anion transportdiffusion in the distal nephron. Besides protein binding which systems. 2.) If a zwitterion has a surplus negative charge (suchdetermines the filtered amount, proximal tubular net secretion as, cefsulodin) it interacts with the PAH and sulfate transporter,or reabsorption are the main variables of drug or xenobiotic but not with the NMN transporter. 3.) "Normal" monocar-excretion. By evaluating correlations of molecular structure boxylic cephalosporins (that is, 6315 S Shionogi) and amino-and interaction with the contraluminal anion transport systems cephalosporins (cephalexin and cefadroxil) behave like thewe made the first step in a new approach to understand net respective penicillin compounds; they show a moderate to lowsecretory or reabsorptive behavior of a variety of diuretics and affinity toward the PAH system. Very interesting is the behav-antibiotics on the cellular level. With some substances our data ior of the aminothiazol compounds cefotaxime, ceftriaxone andalready explain their net transport behavior, at least in a cefodizime. Cefotaxime showed only a small interaction, butqualitative way, and with others the non-consistence of our with an additional electronegative group, that is, enolic OH incontraluminal interaction data with clearance data indicate that ceftriaxone and a second carboxylic group in cefodizime, theafter binding to the anion transporters further transport steps interaction with the PAH system increased. Furthermore, anare rate limiting in transtubular transport, that is, translocation interaction with the sulfate system was seen. Unfortunately, nothrough the respective transporter(s) or transport through the correlation of our data gained in the rat with the renal plasma-anion transporter(s) at the opposite cell side. In addition, free clearances could be established when measured in humansparallel and counter transport through other anion transporters [63]. Thus, cephaloridine with a plasma-free clearance of 160at either cell side must be considered. For practical purposes it mllmin, cefsulodin with115, ceftriaxone with 150 mI/mm use,will be satisfactory to define the main route of transtubular as our data show, different contraluminal transport systems: thetransport for a given drug or xenobiotic, and to find out whether PAH plus sulfate transporter or the NMN transporter. Thus,existing side routes can be neglected. for these substances no or an only small net secretion seems to exist, which was also shown in stop flow studies with cephalo- Acknowledgment ridine [591.Onthe other hand, cefotaxime and cephalexin with a plasma-free clearance of240 mI/mm in humans show only We thank Dr. M. Nakamura, Shionogi Research Laboratories, Shion- a small interaction with the PAH transport system in the rat. ogi & Co., Osaka, for the cephalosporin Shionogi 6315-S. Cephaloridine is an example for a nephrotoxic drug [64—69]. Its nephrotoxicity seems to correlate with the intracellular Reprint requests to Karl J. U/inch, Max-Planck-Institut für Biophy- sik, Kennedyallee 70, D-6000 Frankfurt/Main 70, Federal Republic of concentration of this drug [58, 70]. Probenecid, sulfonamidesGermany. and other organic anions were shown to inhibit cephaloridine nephrotoxicity in mice and chickens [59], while organic cations References were shown to augment it in rabbits [71, 72]. If these substances act via modification of the intracellular cephaloridine concen- 1. ULLRICH KJ, RUMRICH G: Contraluminal transport systems in the tration, probenecid should act by inhibiting contraluminal up- proximal renal tubule involved in secretion of organic anions. Am J take as shown for rabbit [58] and dog [56] or by augmenting Physiol 254:F453—F462, 1988 2. ULLRICH KJ, RUMRICH G, KLOSS S: Contraluminal para-aminohip- luminal efflux. In contrast, the organic cations should act by purate (PAH) transport in the proximal tubule of the rat kidney. IV. augmenting contraluminal uptake or inhibiting luminal efflux, Specificity: mono- and polysubstituted benzene analogs. Pflügers the latter being suggested for rabbit [72]. Since cephaloridine Arch 413:134—146, 1988 exerted inhibition only against the contraluminal organic base 3. WEINER IM: Transport of weak acids and bases, Chapter 17, in Handbook of Physiology, Sect. 8: Renal Physiology, edited by transport system in our experiments in rats, but none against ORLOFF J, BERLINER RB, Washington, American Physiological the contraluminal anion transport systems, we would argue that Society, 1973, p. 521—554 there exist considerable species differences. Conclusions about4. Dsr'oi'ouios A: A definition of substrate specificity in renal nephrotoxicity, transport and interaction of different transport transport of organic anions. J Theoret Biol 8:163—192, 1965 systems are only allowed if the pertinent data are from the same 5. MØLLER JV, SHEIKH MI: The renal organic anion transport system: Pharmacological, physiological and biochemical aspects. Pharma- species. For future studies it seems to be possible to obtain col Rev 34:315—358, 1982 more information about the complicated interactions: 1.) by 6. FRITZSCH G, HAA5E W, RUMRICH G, FASOLD H, ULLRICH KJ: A performing similar interaction studies as in this study with the stopped flow capillary perfusion method to evaluate contraluminal transport parameters of methylsuccinate from interstitium into luminal transport systems, 2.) by application of '9F-NMR- renal proximal tubular cells. Pflugers Arch 400:250—256, 1984 measurements of clearance and intracellular concentrations of 7. ULLRICH KJ, RUMRICH G, KLOSS S: Contraluminal sulfate trans- fluorinated cephalosporins and interaction studies with test port in the proximal tubule of the rat kidney. I. Kinetics, effects of substrates for the different transport systems, 3.) by application K, Na, Ca2, W and anions. Pflugers Arch 402:264—271, 1984 Ulirich et al: Contraluminal organic anion and cation transport 87

8. ULLRICHKJ, RUMRICH G, FRITZSCH G,KLOSSS: Contraluminal 30. ODLIND B, BEERMANN B: Renal tubular secretion and effects of para-aminohippurate(PAH) transportin the proximal tubule of the furosemide. ClinPharmacol Ther 6:784—790,1980 rat kidney. I. Kinetics, influence of cations, anions and capillary 3!. KITZEN JM: Piretanide.CardiovascDrugs 3:49—69,1985 preperfusion. PflügersArch 409:229—235,1987 32. MAREN TH: Renal carbonic anhydrase and the pharmacology of 9. ULLRICH KJ, PAPAvA5sILI0U F, FRITZSCH G: Contraluminal N1- sulfonamide inhibitors, in Handbookof Experimental Pharmacol- methylnicotinamid (NMN) transport in the proximal tubule of the ogy, Vol.24, edited by EICHLER 0, FARAH A, HERKEN H, WELCH rat kidney. I. Kinetics, influence of cations and anions. (manuscript AD, Berlin, Heidelberg, New York, Springer-Verlag, 1969, pp. in preparation) 195—256 10.ULLRICHKJ, RUMRICH G, FRITZSCH G, KLOSS S: Contraluminal 33. PETERS G, ROCH-RAMEL F: Thiazide diuretics and related drugs, in para-aminohippurate (PAH) transport in the proximal tubule of the Handbookof Experimental Pharmacology, Vol.24, edited by ratkidney.H. Specificity: Aliphatic dicarboxylic acids. P.flugers EICHLER 0, FARAH A, HERKEN H, Welch AD, Berlin, Heidelberg, Arch 408:38—45,1987 New York, Springer-Verlag, 1969, pp. 257—385 11.FRITZSCHG, RUMRICH G, ULLRICH KJ: Anion transport through 34. BOWMAN RH: Renal secretion of 35S-furosemide and its depression the contraluminal cell membrane of renal proximal tubule: The by albumin binding. AmJ Physiol 229:93—98,1975 influence of hydrophobicity and molecular charge distribution on 35.WEINERIM, BLANCHARD KC, MUDGE GH: Factors influencing the inhibitory activity of organic anions. BiochimBiophysActa 978: renal excretion of foreign organic acids. AmJ Physiol 207:953—963, 249—256, 1989 1964 12. HANSCH C, Leo A: Editors, in Substituentconstants for correla- 36. PRITCHARD JB, BEND JR: Mechanisms controlling the renal excretion analysis in chemistry and biology. NewYork, John Wiley and tion of xenobiotics in fish: Effects of chemical structure. Drug Sons, 1979 Metabol Rev 15:655—671,1984 13. ESSIG A: inhibition of renal transport of p-aminohip- 37. HONG SK, GOLDINGER JM, SONG YK, KOSCHIER FJ, LEE SH: Competitive Effect of SITS on organic anion transport in the rabbit kidney purate by analogous of chiorothiazide. AmJ Physiol 201:303—308, 1978 1961 cortical slice. AmJ Physiol 234:F302—F307, 14. BEYERKH:Factors basic to the development of useful inhibitors of38. KOSCHIER FJ, ACARA M: Transport of 2,4,5-trichiorophenoxyace- tate in the isolated perfused rat kidney. JPharmacol Exp Ther 208: renal transport mechanisms. Archmt Pharmacodyn 98:97—117, 287—293, 1979 1954 39. BEYER KH, BAER JE, MICHAELSON JK,Russo HF: Renotropic 15.MEISELAD, DIAMOND HS: Inhibition of probenecid uricosuria by characteristicsof ethacrynic acid: A phenoxyacetic saluretic-di- J Physiol 232:F222— pyrazinamide and para-aminohippurate. Am uretic agent. JPharmacol Exp Ther 147:1—22,1965 F226, 1977 40. SNOW IB, MAASS AR: Renal sites of natriuretic and uricosuric 16. WEINER TM, WASHINGTON JA, MUDGE GH: On the mechanism of activity of ticrynafen in mongrel dog. Nephron23(Suppl. 1):15—20, action of probenecid on renal tubular secretion. BullJohns Hopkins l979 Hosp 106:333—345,1960 41. LEMIEUX G, VINAY P, PAQUIN J, GouGoux A: The renal excretion 17. KRAMP RA, LENOIR RH, DENEF J, GHYS A:Effect of the diuretic of tienilic acid (Ticrynafen). A new diuretic with uricosuric prop- torasemideon p-aminohippuric acid transport in the rat. DrugRes erties. (abstract) JClin Chem Clin Biochem 17:420,1979 35:1536—1541,1985 42. KOSCHIER FJ, HONG SK, BERNDT WO: Serum protein and renal 18. SHEIKH MI, STAHL M: Characteristics of accumulation of proben- tissue binding of 2,4,5-trichlorophenoxyacetic acid. ToxicolAppI ecid by rabbit kidney cortical slices. AmJ Physiol 232:F5l3—F523, Pharmacol 49:237—244,1979 1977 43. KOECHEL DA: Ethacrynic acid and related diuretics: Relationship 19. SHEIKH MI, STAHL M, JACOBSEN C: A comparative study on the of structure to beneficial and detrimental actions. AnnRev P/jar- accumulation of probenecid and analogues in rabbit kidney tubules macol Toxicol 21:265—293,1981 in vitro. BiochemPharmacol 28:15—22,1979 44. DETTLI L: Pharmakokinetische Daten für die Dosisanpassung, in 20. SHEIKH MI, MØLLER JV, JACOBSEN C, MAXILD J: Effect of Arzneimittel-Kompendiumder Schweiz, Vol.2 (9th ed), editedby hydrocarbon chain length on renal transport of monosubstituted MORAUTJ, Basel, Documed AG, 1988, pp. 329—337 sulfamyl benzoic acid derivatives and probenecid. BiochemPhar- 45. KLAASSEN CD, FITZGERALD TJ: Metabolism and biliary excretion macol 28:2451—2456,1979 of ethacrynic acid. JPharmacol Exp Ther 191:548—556,1974 21. BERNER W, KINNE R: Transport of aminohippuric acid by plasma 46. GREVEN J: Renal transport of drugs, in RenalTransport of Organic membrane vesicles isolated from rat kidney cortex. PflügersArch Substances, editedby GREGER R, LANG F, SILBERNAGL S, Hei- 361:269—277,1976 delberg, New York, Springer-Verlag, 1981, pp. 262—277 22. SHIMADA H, MOEWES B, BURCKHARDT G: Indirect coupling to 47. BEYER KH: Factors basic to the development of useful inhibitors of Na4 of p-aminohippuric acid uptake into rat renal basolateral renal transport mechanisms. ArchIntern Pharmacodyn 98:97—117, membrane vesicles. Am JPhysiol 253:F795—F801, 1987 1954 23. WEINER TM, WASHINGTON JA, MUDGE GH: Studies on the renal 48. OVERBOSCH D, VAN GULPEN C, HERMANS J, MATTIE H: The effect excretion of salicylate in the dog. BullJohns Hopkins Hosp 105: of probenecid on the renal tubular excretion of bencylpenicillin. Br 284—297, 1959 J Clin Pharmacol 25:51—58, 1988 24. MAREN TH: Carbonic anhydrase inhibition. IV. The effect of 49. BEYER KH, WOODWARD R, PETERS L, VERWEY WF, MATTIS PA: metabolic acidosis on the response of diamox. BullJohns Hopkins The prolongation of penicillin retention in the body by means of Hosp 98:159—183,1956 para-aminohippuric acid. Science100:107—108,1944 25. GEMBAM,TANIGUCHIM,MATSUSHIMAY:Effect of bumetanide 50. BINS JW, MATTIE H: Saturation of the tubular excretion of on p-aminohippurate transport in renal corticalslices. JPharm Dyn /3-lactam antibodies. BrJ Cliii Pharmacol 25:41—50,1988 4:162—166, 1981 51. EAGLE H, NEWMAN E, MUSSELMAN AD, ROBINSON M, BIRMING- 26.SENFT G: Membrantransport und Pharmaka, in Normaleund HAM M: The renal clearance of penicillins F, G, K and X in rabbits pathologische Funktionen des Nierentubulus, editedby ULLRICH and man. JCliii Invest 26:903—918,1947 KJ, HIERHOLZER K, Bern, Stuttgart, Hans Huber, 1965, pp. 63—81 52.KAMIYAA, OKUMURA K, H0RI R: Quantitative investigation of 27. HooK JB, WILLIAMSON HE: Influence of probenecid and alter- renal handling of drugs in rabbits, dogs and humans. JPharmacol ations in acid-base balance of the saluretic activity of furosemide. J Sci 72:440—443,1983 PharmacolExp Ther 149:404—408,1965 53. ABRAHAM EP: Cephalosporins 1945—1986. Drugs34(Suppl2):1—14, 28. FRIEDMAN PA, ROCH-RAMEL F: Hemodynamic and natriuretic 1987 effects of bumetanide and furosemide in the cat. JPharmacol Exp 54. WRIGHT AJ, WILKOWSKE Ci: The penicillins. MayoClin Proc 62: Ther 203:82—91,1977 806—820, 1987 29. ARSLAN Y, DiEzi J: Depression of the natriuretic effect and the 55. ELKS J: Structural formula and nomenclature of the cephalosporin urinary excretion of furosemide by probenecid. (abstract) Kidney antibiotics. Drugs34(Suppl 2):240—246, 1987 mt 5:309,1974 56. KASLIER JS, HOLOHAN PD, Ross CR: Effect of cephaloridine on the 88 Ui/richet al: Contra/urn/na!organicanion and cation transport

transport of organic ions in dog kidney plasma membrane vesicles. 65. ULLRICH Ki, FA5OLD H, RUMRICI-I G, KLOSS S: Secretion and J Pharmaco/ Exp Ther 225:606—610, 1983 contraluminal uptake of dicarboxylic acids in the proximal convo- 57. Irui K!, TAKANOM,OKANOT,H0RI R: H-gradient-dependent lution of rat kidney. Pflugers Arch 400:241—249, 1984 transport of aminocephalosporins in rat renal brush border mem- 66. Kuo CH, TUNE BM, HOOK JB: Effect of piperonyl butoxide on brane vesicles: Role of H/organic cation antiport system. J organic anion and cation transport in rabbit kidney. Proc Soc Exp Pharmaco! Exp Ther 233:181—185, 1985 Biol Med 174:165—171, 1983 58. TUNE BM, FERNHOLT M, SCHWARTZ A: Mechanism of cephalori- 67. KUO CH, MAlTA K, SLEIGHT SD, HOOK JB: Lipid peroxidation: A dine transport in the kidney. J Pharmaco! Exp Ther 191:311—317, possible mechanism of cephaloridine-induced nephrotoxicity. To- 1974 xico! App! Pharmaco! 67:78—88, 1983 59. CHILD KJ, DODDS MG: Nephron transport and renal tubular effects 68. GOLDSTEIN RS, PA5INO DA, HEWITT WR, HOOK JB: Biochemical of cephaloridine in animals. Br J Pharmaco! Chemother 30:354— mechanisms of cephaloridine nephrotoxicity: Time and concentra- 370, 1967 60. INul K!, OKANO T, TAKANO M, SAITO H, HORI R: Carrier- tion dependence of peroxidative injury. Toxicol App! Pharmacol 83:261—270, 1986 mediated transport of cephalexin via the dipeptide transport system in rat renal brush border membrane vesicels. Biochim Biophys Ada 69. COJOCEL C, HANNEMANN J, BAUMANN K: Cephaloridine-induced 769:449—454, 1984 lipid peroxidation initiated by reactive oxygen species as a possible 61. KRAMER W, LEIPE I, PETZOLD E, GIRBIG F: Characterization of mechanism of cephaloridine nephrotoxicity. Biochim Biophys Acta the transport system for /3-lactam antibiotics and dipeptides in rat 834:402—410, 1985 renal brush border membrane vesicles by photoaffinity labeling. 70. WELLES iS, GIBSON WR, HARRIS PN, SMALL RM, ANDERSON RC: Biochim Biophys Acta 939:167—172, 1988 Toxicity, distribution and excretion of cephaloridine in laboratory 62. ULLRICH KJ, RUMRICH G, SCHRINNER E: Cephalosporin (cefo- animals. Antimicrobiol Agents Chernother 1965:863—869, 1966 dizim) transport in the rat proximal renal tubule. (abstract) Kidney 71. W0LD iS, TURNIPSEED SA, MILLER BL: The effect of renal cation /nt29:1256, 1986 transport inhibition on cephaloridine nephrotoxicity. Toxicol App 63. BERGAN T: Pharmacokinetic properties of the cephalosporins. Pharmaco! 47:115—122, 1979 Drugs34(Suppl 2):89—l04, 1987 72. WOLD iS, TURNIPSEED SA: The effect of renal cation transport 64. ULLRICH KJ, JURETSCHKE HP, RUMRICH G, FAHRENHOLZ F, inhibitors on the in vivo and in vitro accumulation and efflux of FASOLD H, SIEGEMUND G: Organic anion transport in the mam- cephaloridine. Life Sci 27:2559—2564, 1980 malian kidney: Continuous '9F-NMR measurements with fluori- 73. BURCKHARDT G, ULLRICH Ki: Organic anion transport across the nated substrates. (abstract) Herbsttagung der Deutschen Physio!o- contraluminal membrane-dependence on sodium. Kidney mt(in gischen Gesel/schaft,Wurzburg,1988 press)