Effects of Antialdosteronics on Plasmatic Hormonal Levels and on Hepatic Sexual Steroid Receptors in Rat A. Di Leo!, P.K. Eagon3, L. Polimeno!, F.W. Guglielmini!, I i' G. Fanizza2 , M. Barone!, G. Zizza!, A.M. Aquilino!, R. Ferrara!, A. Giangasperol, T.E. Starzl4 and A. Francavilla! 1 Dept. of Gastroenterology and 2 Dept. of Obstetrics and Gynecology, University of Bari, Bari, Italy 3 Dept. of Medicine and 4 Dept. of Surgery, Univesity of Pittsburgh, Pittsburgh, Pennsylvania Spironolactone and potassium canrenoate are diuretics widely used for management of cirrhotic ascites. The administration of spironolactone frequently leads to feminization, which has been noted less frequently with the use of potassium canrenoate, a salt of the active metabolite of spironolactone. The use of these two drugs has been associated with decreases in serum testos­ terone levels and in case of spironolactone with a reduction in androgen receptor (AR) activity (8,10,19,20,23,25-28). Considering the critical role of the liver in sex hormone me­ tabolism the study about the effects of these drugs on liver sex hormone receptor state, could add new informations for under­ standing the mechanism of feminization by these two drugs. We report here the effect of spironolactone and potassium canrenoate treatment on the sex hormone receptor and androgen responsive protein status of the liver and the effects of these treatments on serum estrogen and testosteron levels. MATERIALS AND METHODS Animals Three groups of adult male Sprague Dawley rats (240 gr b.w.) were studied. Animals in the control group (group 1) were 242 ANTIALDOSTERONIC DIURETICS AND RAT LIVER ANTIA. injected intraperitoneally with 0.5 ml of a solution of physiologic salin with TWEEN 80 (0.1% v/v). The rats in the other groups received 5 mg of spironolactone (group 2) or 5 mg of Protein conCt potassium canrenoate (group 3) dissolved in the same vehicle. All DNA concentr. animals were injected daily for 21 days and killed by decapita­ method of Burto tion after that time. Cytosolic r the basis of 3 Materials rected for yel receptor conten Estradiol (E2) and Dihydrotestosterone were purchased from bound/mg DNA re Steraloids, Wilton, NH. Spironolactone and Potassium Canrenoate rected for the were from SPA, Milan, Italy. Diethylstilbestrol (DEB), Leupeptin, animal, the tot Benzamidine, Bovine serum Albumin, Sodium Molybdate, Protamine the cytosolic a Sulfate and other buffer component were purchased from Sigma Cytosolic cont Chemical Co., St. Louis, MO. Norit A and Dextran C were obtained activity of ale from Fisher Scientific Co., Pittsburgh, PA. Radioactive and the washe (2,4,6,7,16,17)- 3H -E2 (131 Ci/rnrnol), 17 -methyl- 3H - 0.5% of that f methyltrienolone (3H -RI881) (79 Ci/rnrnol) and nonradioactive recovery of D R1881 were obtained from New England Nuclear, Boston, MA. In­ the homogenate. stagel scintillation fluid was purchased from Packard Instrument Serum testos Co., Downers Grove, IL. The radiolabeled steroids used in these mined by specif studies were assayed periodically for purity by thin layer Equilibrium chromatography on silica gel G in ethyl acetate/hexane/ethanol tions of bindin (85:10:5), and were used only if purity was> 95%. (35) . Statistical Assay of nuclear and cytosolic Sex-Steroid receptors program. Radioactivit Nuclear and cytosolic Sex-Steroid receptors were evaluated by ard TriCarb 543 the method previously described by us (11,14,16-18). Assay of androgen-responsive male estrogen binding protein In spironol Assay for the determination of cytosolic content of a male decrease in tes specific estrogen binding protein (MEB) has been described pre­ hormone levelt' viously (12,34). Briefly, cytosol is pre incubated for 1 h at 0 °c trol animals. with· 500 nM DES to block the estrogen receptor. The cytosol is observed in c· then incubated with 5 nM 3H-E2 in the absence and presence of significant red 5 M unlabeled E2 for 2 h a 0 °c. Bound and free steroids are Cytosolic At; separated by centrifuge-assisted BioGel P-6 chromatography (34). renoate treate This assay is quantitative for MEB and is linear over a broad control animal" range of protein concentration. variations in groups studied 0.25+0.08 nM tively (Tab I). ~"':~",_~~:t\!' ">- . - ~ .. Il'ER ANTIALDOSTEIWNIC D/URETICS AND l?/IT LIVER 2-13 solution of Other methods " in the other or 5 mg of Protein concentrations: method of Bradford (5). <2 vehicle. All DNA concentrations of homogenates and nuclear preparations: by decapita- method of Burton (6). Cytosolic receptor content for each animal was calculated on the basis of 3H -steroid bound/mg cytosol protein, and then cor- rected for yeld of cytosolic protein for gram of liver. Nuclear receptor content was calculated on the basis of 3H -steroid 'urchased from bound/mg DNA recovered in the nuclear preparation, and then cor­ Lum Canrenoate rected for the DNA content of the original homogenate. For each l), Leupeptin, animal, the total liver content of receptor represents the sum of ~e, Protamine the cytosolic and nuclear content based on 1 gram of liver. sed from Sigma Cytosolic contamination of nuclei was assayed by determining the were obtained activity of alcohol dehydrogenase (37) in the homogenate, cytosol Radioactive and the washed nuclei preparation and was found to be less than -methyl- 3H - 0.5% of that found in the nuclear preparation. The average :lonradioactive recovery of DNA in the nuclear preparation was 72.8% of that in :on, MA. In­ the homogenate. lrd Instrument Serum testosterone, estradiol and other hormones were deter­ used in these mined by specific radioimmunoassays as described previously (38). 1y thin layer Equilibrium dissociation constants (Kd's) and the concentra­ :exane/ethanol tions of binding sites were calculated by the method of Scatchard (35) • Statistical analyses were performed using the Student's t-test program. Radioactivity content of samples was determined using a Pack­ ; evaluated by ard TriCarb 5430 Liquid Scintillation System. RESULTS ~ng protein In spironolactone treated animals there is a significant of a male decrease in testosterone levels; all other gonadal and pituitary :escribed pre­ hormone levels in this group are comparable to those of the con­ r 1 h at 0 °c trol animals. In potassium canrenoate treated rats no change was he cytosol is observed in either testosterone or estradiol levels, although presence of significant reductions in progesterone and DHEAS was found. steroids are Cytosolic AR levels (cAR) are significantly higher in K can­ 19raphy (34). renoate treated rats as compared with those observed in either - over a broad control animals or spironolactone treated ones. There were no variations in the affinity of the cAR for its ligand in any groups studied. The Kd values for cAR were 0.26+0.06 nM, 0.25+0.08 nM and 0.31+0.04 nM for group I, II and III respec­ tively (Tab I). 244 ANTIALDOSTERONIC DIURETICS AND RAT LIVER ANTIA The activity of nuclear androgen receptor (nAR) , however, to sacrifice (1- presents a markedly different picture, and is significantly ra ts is ac tuall- decreased in the animals treated with either spironolactone or To determin· potassium canrenoate. competing for a­ As a result of these variations, the total AR content of the they were cap liver changed significantly only in those animals treated with an in vitro ass spironolactone (50% decrease from normal levels). Interestingly, Spironolac to' the activity of total androgen receptors in the spironolactone effective as treated animals shows a decrease proportional to that of plasma cytosol. Howeve­ testosterone. effective comp, canrenoate is i; Tab I: Variation in specific 3H -R1881 in rat liver any concentrati\ The activit: 3H -R1881 specific binding (fmol/g liver) were virtually of cER for E2 v, TOTAL NUCLEUS CYTOSOL PLASMA TESTOSTERONE were 0.26-+{).07 1 (NG/ML) and III respect: (nER) was decree CONTROL 364+62 202+46 162+9.9 1. 77+0.23 treated animal~ content does not SPIRO 170+38 26+7 144+24 0.78+0.20 latter finding (P<0.05) (P<0.05) (P<0.05) values in these K-CAN 347+61 21+8 326+42 1. 53+0. 32 Tab III: Variati (P<0.05) (P<0.05) liver 31- As total hepatic androgen receptor activity and plasma testosterone values were reduced in the spironolactone-treated TOTAl animals, the activity of a hepatic androgen responsive protein, a male specific estrogen binder (MEB), was also assessed (Tab II). CONTROL 623+11 Tab II: Activity of an androgen responsive protein in rat liver SPIRO 549+8' MEB (pmol/mg protein) CONTROL 2.41+1 K-CAN 650+2:': SPIRO o K-CANREO 6.3+1.5 (p<0.05) Sexual dimorp \ The activity of this protein is undetectable in the livers of animals and huma) the spironolactone treated animals; this loss of MEB activity is In male rat: comparable to that seen in rats castrated at least 15 days prior . LIVER ANTIALDOSTERONIC DIURETICS AND RAT LIVER 245 nAR) , however, to sacrifice (14,36). However MEB level in k-carenoate treated Ls significantly rats is actually higher than that observed in the control tats. Ii Lronolactone or To determine whether either of these drugs might interfer by \.' :j , I competing for androgen binding to its receptor, we tested whether ,;' ,i R content of the they were capable of competing for androgen receptor binding in ,; treat.ed with an in vitro assay. Interestingly, Spironolactone, at a 100 and 1000-fold excess, is partially spironolactone effective as a competitor for 3H - R188l binding in rat liver u that of plasma cytosol. However, the strong androgen R188l and DHT are much more effective competitors than is spironolactone. In contrast, k­ canrenoate is incapable of competing for 3H - R1881 binding at ver any concentration tested.