Calorigenic Effect of Norepinephrine Correlated with Plasma Free Fatty Acid Turnover and Oxidation

Daniel Steinberg, … , Elsworth R. Buskirk, Ronald H. Thompson

J Clin Invest. 1964;43(2):167-176. https://doi.org/10.1172/JCI104901.

Research Article

Find the latest version: https://jci.me/104901/pdf Journal of Clinical Investigation Vol. 43, No. 2, 1964

Calorigenic Effect of Norepinephrine Correlated with Plasma Free Fatty Acid Turnover and Oxidation * DANIEL STEINBERG, PAUL J. NESTEL,t ELSWORTH R. BUSKIRK,4 AND RONALD H. THOMPSON (From the Laboratory of Metabolism, National Heart Institute, and the Metabolic Disease Branch, National Institute of Arthritis and Metabolic Diseases, Bethesda, Md.)

The increase in oxygen consumption caused by consumption in man and that this is accompanied administration of epinephrine has been extensively by an increase in turnover of plasma FFA and an studied in animals and in man. Many physiologi- increase in rate of conversion of labeled plasma cal and biochemical correlations have been made FFA to respiratory C1402. All of these effects of and many different hypotheses have been ad- norepinephrine are abolished or radically re- vanced to explain this so-called calorigenic effect, duced when the patient has first been given an in- but there is still no clearly established consensus travenous dose of pronethalol [2-isopropylamino- regarding the mechanism or mechanisms involved 1-(2-naphthyl)ethanol hydrochloride], a drug that (1, 2). inhibits catecholamine stimulation of adrenergic In recent years it has become clear that one of ,8-receptors (8, 9) and that prevents the FFA the most striking metabolic effects of the cate- mobilization induced by catecholamines (10).1 A cholamines is their ability to stimulate mobiliza- preliminary report of these findings has been made tion of depot fat in the form of free fatty acids (11). (FFA) (3). Studies by Fritz, Davis, Holtrop, Methods and Dundee (4) and by Eaton and Steinberg (5) The subjects studied were young, adult, normal, con- have shown, moreover, that the rate of oxidation trol volunteers on regular ward diets, with their total of labeled FFA by isolated skeletal muscle prepa- caloric intake adjusted to maintain constant body weight. rations in vitro is a function of the concentration Metabolic studies were all done after a 12- to 16-hour fast, and subjects remained at rest in bed on the morn- of FFA in the medium. Similar effects of FFA ings of studies. Indwelling plastic catheters were placed concentration on FFA oxidation have been dem- in an antecubital vein of each arm after the skin had been onstrated in rat liver slices (6) and in perfused anesthetized with Xylocaine (2-diethylamino-2',6'-aceto- rat liver (7). We have previously suggested, xylidide). A slow drip of 0.85% NaCl was maintained therefore, that the calorigenic action of catechol- to keep the catheters open. The subj ects were then taken to the metabolic chamber in a wheel chair. The amines might be due, at least in part, to their ef- construction and operation of the metabolic chamber fect in mobilizing FFA (5). have been fully described by Buskirk, Thompson, Moore, The present clinical studies were undertaken to and Whedon (12). At least 30 minutes was allowed to explore this possibility further. Because the meta- establish stable control values for rate of oxygen con- bolic effects of epinephrine are somewhat more sumption. Blood samples were drawn from one arm through a 3-way stopcock and delivered into a chilled complex than those of norepinephrine, in that tube containing heparin. Infusions of drugs, or labeled the former actively mobilizes glucose as well as palmitate, or both, were given into the opposite arm FFA, the present studies were done primarily with Bowman finger pumps. with norepinephrine. It is shown that infusion Plasma FFA were determined by Dole's method (13) of norepinephrine increases the rate of oxygen using isobctane (2,2,4-trimethylpentane) in place of hep- 1 Since these studies were completed, the Research De- * Submitted for publication August 12, 1963; accepted partment of Imperial Chemical Industries, Ltd., Maccles- October 3, 1963. field, England, manufacturers of pronethalol (Alderlin), tPresent address: Department of Medicine, Royal has found that mice on chronic high dosage show a sig- Melbourne Hospital, Melbourne, Australia. nificant incidence of locally malignant lymphosarcomata t Present address: Laboratory of Applied Physiology, of the thymus gland. Further use of the drug in clini- Pennsylvania State University, State College, University cal investigation should probably await thorough eva'u- Park, Pa. ation of these preliminary findings. 167 168 STEINBERG, NESTEL, BUSKIRK, AND THOMPSON

TABLE I Effects of infused norepinephrine on FFA levels, FFA turnover, and oxygen consumption in normal control subjects

Norepinephrine Plasma Plasma Percentage 02 Percentage Subject, administration FFA FFA change in con- change in sex, age, Dosage Blood Pulse concen- turn- FFA sump- 02 con- wt rate Time* pressure rate tration over turnover tion sumption ,ug/min min mm Hg pEq/ml pEq/min % ml/min % Control values 100/70 60 0.69 326 225 C.H. (I), 6 12 118/85 47 0.85 459 + 41 245 + 9 M, 21, 6 22 1.14 533 + 64 255 +13 66.6 kg 12 15 130/90 45 1.29 544 + 66 245 + 9 12 26 1.38 540 + 66 265 +18 Control values 95/65 70 0.36 215 C.H. (II), Placebo M, 21, infusionj 10 90/65 55 0.33 210 - 2 66.6 kg Control values 0.46 211 12 10 130/90 47 0.93 235 +11 Control values 100/60 55 0.46 205 B.L., 10.5 15 110/80 48 1.16 221 + 8 M, 23, Control valuest 105/60 47 0.54 205 66.1 kg 10.5 16 120/80 47 1.42 229 +12 Control values 110/65 58 0.48 226 192 B.L., 6 10 115/80 48 0.69 280 + 24 202 + 5 M, 23, 6 27 1.65 677 +200 210 + 9 66.1 kg 12 22 124/84 46 1.61 573 +154 231 +20 20 18 150/90 50 1.81 250 +30 L.C., M, 25, Control values 100/76 60 0.90 333 235 72.6 kg 18 16 140/110 60 1.57 506 + 52 286 +22 S.P., Control values 90/60 50 0.39 155 F, 17, 7.2 13 100/70 48 1.21 165 + 6 60.3 kg 14.4 14 1.69 181 +17 14.4 25 120/80 60 1.82 180 +16

* Times indicate the cumulative number of minutes from the start of administration at each dosage rate. Except where indicated by inter- vening control values, dosage rates were changed without interrupting the infusion. t Saline infused by Bowman pump with identical routine of blood pressure readings and blood samplings that accompanied norepinephrine infusions. Infusion identified to patient as "norepinephrine." t Obtained 53 minutes after discontinuing first norepinephrine infusion. tane. Blood glucose was measured enzymatically by the tracting by Dole's method, re-extracting the F-FA from glucose oxidase method described by Keston (14). the isooctane layer into alcoholic KOH, acidifying the Reagents (Glucostat) were obtained commercially.2 latter, and finally re-extracting the FFA into isooctane. Plasma lactate levels were determined enzymatically (15). The isooctane was dried in a counting vial under a Plasma FFA turnover was determined by using a con- stream of N2, the residue was redissolved in toluene stant intravenous infusion of palmitate-1-C'4. The basis containing 0.5% 2,5-diphenyloxazole, and radioactivity for this method has been fully discussed by Armstrong was assayed in a Packard Tri-Carb liquid scintillation and associates (16). The infusion solution was prepared spectrometer. In several experiments the lipids in the by adding a tracer amount of sodium palmitate-1-C'4 to final isodctane extract were fractionated on silicic acid a solution of human serum albumin (5 to 7.5%o). The columns (17). No significant amounts of radioactivity solutions were prepared for clinical use and were tested were recovered with the phospholipid fraction. for sterility and absence of pyrogens.3 The labeled pal- For measurement of C1402 production, a measured mitate was diluted in 100 to 150 ml of 0.85%o NaCl and fraction of the gas stream from the metabolic chamber infused at a rate of 1 to 1.5 ml per minute. Within 15 was diverted and collected in 4- to 5-minute periods in to 20 minutes the total FFA radioactivity per milliliter Douglas bags. The gas from these bags was slowly of plasma had reached a plateau value that did not then pulled through a gas-flow meter and delivered through vary more than + 10% during the control period. a sintered glass diffuser into a column of NaOH. A Plasma FFA radioactivity was measured by first ex- Ba(OH)2 trap connected in series showed that collection 2 of CO, was complete. Three-ml samples of the NaOH Worthington Biochemical Corp., Freehold, N. J. were added to 1 g of fluorescence-grade anthracene,5 and 3 Performed by Mr. William H. Briner, Radiopharma- ceutical Service, National Institutes of Health, Bethesda, 4 Packard Instrument Co., La Grange, Ill. Md. 5 Distillation Products, Inc., Rochester, N. Y. CALORIGENIC EFFECT OF NOREPINEPHRINE AND FFA TURNOVER 169 radioactivity was assayed in the liquid scintillation spec- by intravenous infusion of norepinephrine are trometer ( 18). summarized in Tables I and II. In Table the Pronethalol (Alderlin) was generously donated.0 lI Norepinephrine (Levophed) was diluted in 0.85%o NaCl responses to a second norepinephrine infusion, to a final concentration of 6.6 ,ug per ml (expressed as given immediately after administration of pro- the base). nethalol, are shown for ready comparison with the Results responses in the control state. The effects of The changes in blood pressure, pulse rate, FFA norepinephrine in the control state will be dis- concentration, and oxygen consumption produced cussed first. Oxygen consumption. In every case infusion 6 Ayerst Laboratories, New York, N. Y. of norepinephrine at dosage rates of 10 to 21 ug

TABLE II Blocking effect of pronethalol on the increased FFA turnover and hypermetabolism induced by norepinephrine

Norepinephrine Plasma Plasma Percentage 02 Percentage Subject, administration FFA FFA change in con- change in sex, age, Dosage Blood Pulse concen- turn- FFA sump- 02 con- wt rate Time* pressure rate tration over turnover tion sumption pg/misn min mm Hg MEq/ml pEqlmin % mi/min % Before pronethalol Control values 110/65 74 0.69 420 220 18 12 140/85 52 0.86 500 + 19.0 246 +11.8 W.S., 18 16 M, 23, +2t 1.36 790 +135.5 262 +19.1 65.1 kg After pronethalol Control values 110/75 70 0.86 430 235 18 8 0.73 430 0.0 197 -16.2 18 16 142/90 50 0.69 400 - 7.0 230 - 2.1 Before pronethalol Control values 96/64 75 0.37 258 247 D.C., 10 15 150/100 85 0.90 444 + 72.0 344 +39.2 M, 27, After pronethalol 79.1 kg Control values 95/58 72 0.39 298 274 10 7 115/80 43 0.41 172 - 42.3 260 - 5.1 10 9 220 -19.7 10 15 130/85 48 0.64 302 + 1.3 295 + 7.7 Before pronethalol Control values 110/68 55 0.70 270 205 16 12 140/95 42 1.05 300 + 11.1 256 +24.8 B.L. (I), After pronethalol M, 23, Control values 112/60 59 0.68 270 184 66.1 kg 16 11 140/100 37 0.64 190 - 29.6 156 -15.2

Control valuesi 118/58 65 0.68 270 215 16 9 140/105 38 0.59 140 -23.9 Before pronethalol Control values 100/68 77 0.86 450 215 R.B., 13 18 125/90 55 1.13 588 + 30.7 235 + 9.3 M. 35, 21 14 140/105 45 1.34 572 + 27.4 245 +13.9 86.4 kg After pronethalol Control values 110/68 83 0.86 460 229 21 14 140/90 44 0.69 298 - 35.2 221 - 3.5 Before pronethalol Control values 110/60 78 0.52 240 B.L. (II). 18 13 155/83 57 1.16 306 +27.5 M, 23, After pronethalol 66.1 kg Control values 0.85 236 18 7 160/90 45 0.56 208 -12.6 18 14 0.68 229 - 3.8

* Times indicate cumulative number of minutes from start of infusion at each dosage rate. Dosage rates were changed without interrupting the infusion. t Values determined 2 minutes after discontinuing the norepinephrine infusion. Complete record for this study shown in Figure 1. I Control values obtained 29 minutes after discontinuing first infusion of norepinephrine. 170 STEINBERG, NESTEL, BUSKIRK, AND THOMPSON per minute (0.13 to 0.31 ptg per kg per minute) Because fear and anxiety can cause elevations significantly increased the rate of oxygen con- of FFA and might lead to increases in oxygen sumption. The value at the peak of the response, consumption, we restudied patient C. H., a some- reached toward the end of the 15- to 25-minute what apprehensive individual, following the stand- infusion period, was 21 ± 8% above control val- ard protocol but infusing only 0.85%o sodium chlo- ues (11 cases shown in Tables I and II). The ride. The usual control blood samples were taken, responses ranged from + 11 to + 397o. the Bowman pump was started, and the recording FFA levels and turnover. Basal FFA levels in technician was told to mark "norepinephrine the plasma, determined after the subjects were in started" at that time. There were no changes of position in the metabolic chamber and just before any significance in plasma FFA level or oxygen the norepinephrine infusion was started, were consumption (Table I, C. H., II). After a resting 0.58 ± 0.19 uEq per ml. At the time when the interval of 20 minutes, the same protocol was fol- maximal response in oxygen consumption was lowed, this time with norepinephrine in the infu- reached, FFA levels had risen to 1.28 ± 0.27 uEq sion. Both plasma FFA and oxygen consumption per ml, an increase of 127 ± 57%o over basal rose significantly. values. Conversion of palmiitate-l-C14 to C1402. In In seven subjects FFA turnover was deter- two studies measurements of respiratory C1402 mined before and during norepinephrine treat- were made before and during norepinephrine ad- ment by using a continuous intravenous infu- ministration as shown in Table III. In both cases sion of palmitate-1-C14. In every case norepi- the net rate of production of C1402 increased. nephrine caused an increase in turnover, but the The plasma FFA levels rose and the plasma FFA response was variable, ranging from 11 to 154%o specific radioactivity fell at the same time. Thus above control values with a mean rise of 74 ± the calculated minimal rate at which plasma FFA 53%o (Tables I and II). The percentage increase was being converted to C1402 rose to a greater in FFA turnover was greater than the percentage extent than would be indicated by considering the increase in oxygen consumption in six of the increase in absolute rate of C1402 production seven cases. The mean percentage increase in alone. The changes in oxidation of plasma FFA FFA turnover for the seven cases studied (74%) calculated from concurrent measurements of FFA was more than three times the mean percentage specific radioactivity in plasma and total C1402 in increase in oxygen consumption (24%o). respiratory gas represented increases of approxi- Pulse and blood pressure. Within a minute or mately 200% (Table III). two after the infusion was started, blood pres- These calculations do not take account of the sure rose and pulse rate decreased. The brady- large size and relatively slow turnover of the body cardia, presumably a reflex response to the rise bicarbonate pool. This will introduce a lag be- in blood pressure, was generally most marked dur- tween the time that stimulation of the rate of FFA ing the first 5 minutes, the heart rate returning oxidation in the tissues begins and the time when toward control values when the infusion was a new steady state rate of appearance of C14 in continued at a constant rate. At the time when respiratory CO2 is attained. The measurements in the maximal changes in oxygen consumption were the control period were made at least 30 minutes observed, the mean decrease in pulse rate was 9 after starting the infusion of labeled palmitate. beats per minute. At that time systolic blood The C1402 output in successive collections during pressure had risen 36 mm and diastolic 26 nmm of the control period was very nearly the same, indi- Hg above control levels. cating that a steady state had been achieved, i.e., A few patients reported headache or pounding the specific radioactivity of the bicarbonate pool in the head, and a few noted difficulty in "getting was relatively constant. The norepinephrine infu- a deep breath" during the first few minutes of the sions, however, extended over a limited time pe- infusion. These symptoms were transient, and riod (14 and 17 minutes), and the specific radio- most patients had no discomfort during the latter activity of the bicarbonate pool probably had not part of the infusion period. There were no other yet reached a new steady state level. Thus the adverse reactions. estimated norepinephrine effects on the rate of CALORIGENIC EFFECT OF NOREPINEPHRINE AND FFA TURNOVER 171

TABLE III Effects of norepinephrine on turnover and oxidation of serum FFA; modification by pronethalol treatment

Norepinephrine, Plasma Plasma Rate of Minimal Subject, administration FFA Plasma FFA respiratory oxidation sex, age, Dosage concen- FFA turn- C1402 of plasma 02 con- wt rate Time* tration SA over production FFAt sumption pg/min min pg/ml cpm/pEq pEqi cpm/min pEqi mil/min min min Before pronethalol Control values 0.36 308 201 3,500 11.3 231 0.41 273 264 3,800 13.9 250 10 7 0.66 254 288 4,100 16.1 318 D.C., 10 14 0.84 146 416 4,900 33.6 332 M, 27, 79.1 kg After pronethalol Control values 0.40 228 316 4,000 17.5 268 10 9 0.58 258 279 4,000 15.5 260 10 13 0.61 248 290 4,800 19.3 278 Control values 0.82 138 312 2,750 20.0 228 L.C., 0.90 129 333 2,750 21.3 235 M, 25, 18 12 1.31 114 403 5,750 50.3 293 72.6 kg 18 17 1.57 85 506 6,000 70.6 286

* Times indicate cumulative number of minutes from start of infusion at given dose rate. t Rate of production of respiratory C1402 divided by mean specific radioactivity of serum FFA determined at start and at end of 4-minute collection of respiratory CO2 (counts per minute/minute)/(counts per minute/microequivalezit).

III may palmitate oxidation calculated in Table 80_ B. L. true llJ ELI 70 M 23 underestimate the magnitude of the stimula- X, 60 _ a tion. 50 _ 40_ Effects of pronethalol. In six experiments pro- 30_ nethalol was given intravenously (75 to 100 mg 170 over a 10-minute period) after the rate of oxygen - consumption had returned to control levels fol- I 130 discontinuing of the control norepinephrine E 90- lowing 50L_ infusion. A second infusion of norepinephrine 1.1_ was then given at the same dosage rate used in

tion, the calorigenic action, was also blocked. (In the exceptional case [B.L., I, Table II], the Preliminary studies have shown that the calori- response in FFA turnover was less than 25% of genic action of epinephrine in man is likewise the next lowest response and only 10% of the blocked by pronethalol (29). The concomitance of response observed in the same patient given the the two effects and the fact that both are blocked same dose of norepinephrine on another occasion.) by pronethalol is compatible with, but does not Two points should be considered in evaluating the establish, a cause and effect relationship between significance of this relationship. First; as dis- the FFA-mobilizing action and the calorigenic ac- cussed above, we cannot be certain about the true tion of catecholamines. The catecholamines have extent to which the FFA turned over in the many physiological activities in addition to their plasma compartment are being oxidized. Second, fat-mobilizing activity. The possibility that other the absolute values for turnover by the constant catecholamine effects are more relevant to the infusion method may be too low. If there were calorigenic action and that these are simultaneously any important re-entry of radioactive FFA from inhibited by pronethalol cannot be ruled out. At tissues into plasma, this would constitute an ad- least, the fat-mobilizing action of the hormones ditional "input" of labeled material over and and their activities relevant to the calorigenic ef- above that being infused and should be added to fect are both blocked by pronethalol, and the re- the value for "counts per minute infused per min- ceptors involved thus fall operationally into the ute." The fact that a stable value for plasma category of f8 receptors. FFA specific radioactivity is reached within 10 to The degree to which FFA are diluted in pools 20 minutes indicates that any such tissue sources of nonradioactive fatty acids after leaving the must quickly reach a plateau specific radioactivity. plasma and before being oxidized is not known. Still there might be considerable cycling into and It is therefore not possible to draw firm con- out of a radioactive extravascular pool, and this clusions regarding the rate at which fatty acids turnover would go undetected. The fact that the are being oxidized from data of the kind presented absolute values for turnover obtained in the pres- here. A minimal figure can be calculated by as- ent study are in the same range as those obtained suming no dilution, and as shown in Table III, by Fredrickson and Gordon (30) using the single such a calculation gives values only 5 to 10% injection technique suggests that the potential er- that of the total turnover in the plasma com- ror discussed cannot be large, but further studies partment. Oxidation of this small amount of are in progress to evaluate this. In any case, the FFA would account for only a very small frac- true turnover would, if anything, be higher than tion of the observed oxygen consumption, either that estimated here, and the extra substrate made in the basal state or during administration of available could, even if only partially oxidized, norepinephrine. It seems highly probable that account for the observed increments in oxygen there is considerable dilution by extravascular consumption. pools of fatty acids (nonesterified and esterified) Previous studies have shown that the rate of and that the actual amounts being oxidized are oxidation of labeled long-chain fatty acids by much higher. muscle and by liver in vitro is increased when If the extra amount of FFA mobilized under the their concentration in the incubation medium is influence of norepinephrine does indeed represent increased (4-6). Recently, we have been able to the extra substrate being oxidized, it should be demonstrate an increase in rate of oxygen utiliza- possible to correlate in some measure the observed tion by perfused rat liver exposed to perfusing increment in oxygen consumption with the amount fluid containing a high concentration of FFA of oxygen needed to oxidize the newly mobilized (7). The possibility that the calorigenic effect FFA. From the tabulated data, it can be calcu- of the catecholamines and, by analogy, the hyper- lated that in eight of the nine studies in which metabolism of the hyperthyroid state, are directly turnover was measured, the amount of oxygen attributable to an increase in utilization of FFA needed to oxidize the extra FFA mobilized during made available to the peripheral tissues at high norepinephrine administration equals or exceeds concentrations has been suggested (5). Earlier the observed increment in oxygen consumption. studies by Cori and Cori (31) led to the conclu- 174 STEINBERG, NESTEL, BUSKIRK, AND THOMPSON sion that the larger fraction of the extra caloric ster, Issacs, Osgood, and King found that epi- consumption after epinephrine administration was nephrine and norepinephrine had approximately attributable to combustion of fat. Carlson and equal calorigenic potency in dogs but, as in the Hsieh have proposed that norepinephrine may be present studies, norepinephrine did not raise se- of great importance in the elevated heat produc- rum lactate levels (23). The hyperglycemia ac- tion of cold-adapted animals (32, 33). Recent companying epinephrine administration has also studies show that adipose tissue from cold-adapted been proposed as a factor in the calorigenic re- rats releases FFA more rapidly than tissue from sponse (1). Norepinephrine is much less po- control rats (34, 35). Cold-adapted rats show an tent than epinephrine in stimulating glycogenoly- exaggerated calorigenic response to norepineph- sis, and at the dosages used in the present stud- rine, and their adipose tissue appears to be more ies, there was only a minimal increase in blood sensitive to the fat-mobilizing effects of norepi- glucose levels (maximal levels of 94 to 109 mg nephrine (34-37). Thus there is considerable cir- per 100 ml). Intravenous administration of glu- cumstantial evidence relating the elevated meta- cose at rates that raised blood glucose levels to bolic rate of rats exposed to cold to catecholamine- values much higher than those reached during stimulated fat-mobilization. norepinephrine infusion (over 250 mg per 100 It is possible that the association between the ml) did not cause any increase in oxygen con- FFA-mobilizing action and the calorigenic action sumption. Although hyperglycemia and hyper- of catecholamines is indirect, even though causally lacticacidemia may play some role in the hyper- related. For example, the extra FFA made metabolic action of epinephrine, it seems unlikely available may be converted to another substrate that these play an important role in the calori- form before oxidation. The work of Havel and genic action of norepinephrine as used in the co-workers has shown that FFA are very rapidly present studies. incorporated into triglycerides in the liver and Another factor that might contribute to the then resecretedi in low-density lipoproteins (38). calorigenic action of norepinephrine is an increase Studies by Gidez, Roheim, and Eder (39) and by in cardiac work. Since cardiac metabolism only Nestel and Steinberg (7) show that the output accounts for about 5 % of total body oxygen con- of triglycerides by the isolated perfused rat liver sumption in man (42), it seems unlikely that this is increased when the FFA concentration of the could be increased enough to cause the increases perfusing fluid is elevated. It would be useful to in rate of oxygen consumption induced by nor- know if the turnover of the triglycerides in low- epinephrine in these studies. Moreover, pre- density lipoproteins is increased by administration treatment with pronethalol did not importantly of catecholamines. A second possibility is that modify the changes in blood pressure and pulse the FFA are first converted to ketone bodies in rate induced by norepinephrine, whereas it did the liver and then further oxidized by peripheral abolish the rise in oxygen consumption. tissues. The ketone body levels are indeed some- what elevated during catecholamine administration Summary to normal subjects (40). The increment in oxy- Intravenous infusion of norepinephrine (0.13 gen consumption may partly reflect the energy to 0.31 ug per kg per minute) significantly in- used for the breakdown and resynthesis of tri- creased oxygen consumption in fasting young glycerides within the adipose tissue, as proposed adults, the mean increase being 21 + 8% above by Ball and Jungas (41), and the energy re- control values in 11 studies. Concomitantly, quired for re-esterification of FFA mobilized and plasma FFA levels rose 127 ± 57%o above con- then taken up again in the liver and other tissues. trol values, and turnover of plasma FFA rose Lundholm showed that the calorigenic effect of 74 + 53%o. Blood glucose levels increased only epinephrine is well-correlated with the rise in se- very slightly (mean increase of 14 mg per 100 ml rum lactate levels accompanying its administra- in four cases), and changes in plasma lactate tion and that infusion of lactate into rabbits in- levels were of marginal significance. In two duced a rise in oxygen consumption (21). In the cases conversion of palmitate-1-C14 to C140, was present studies, with norepinephrine, there was measured and was shown to be increased 2 to 3 little or no change in serum lactate levels. Brew- times by norepinephrine administration. CALORIGENIC EFFECT OF NOREPINEPHRINE AND FFA TURNOVER 175 When the subjects were given an intravenous ade on glucose and fatty-acid mobilisation in man. dose of 75 to 100 mg of pronethalol, a beta- Lancet 1962, 2, 316. adrenergic blocking agent, before the norepineph- 11. Steinberg, D., P. J. Nestel, E. R. Buskirk, and R. H. Thompson. Relation between fat-mobilization and rine infusion, the rise in oxygen consumption and hypermetabolism induced by norepinephrine and the increase in FFA levels and turnover were triiodothyronine (abstract). J. clin. Invest. 1963, radically reduced or entirely abolished. The 42, 983. changes in blood pressure and pulse rate were 12. Buskirk, E. R., R. H. Thompson, R. Moore, and essentially the same as those observed in the ab- G. D. Whedon. Human energy expenditure stud- ies in the National Institute of Arthritis and sence of the blocking agent. Metabolic Diseases metabolic chamber. Amer. The present findings are compatible with the J. clin. Nutr. 1960, 8, 602. hypothesis that the calorigenic action of norepi- 13. Dole, V. P. A relation between non-esterified fatty nephrine is causally related to its ability to in- acids in p asma and the metabolism of glucose. crease the rate of FFA mobilization. This may J. clin. Invest. 1956, 35, 150. be direct, reflecting an increased rate of utilization 14. Keston, A. S. Abstracts of papers, 129th Meeting of the Amer. Chem. Soc., April 1956, p. 31C. of the FFA themselves, or indirect, reflecting uti- 15. Hohorst, H. J., F. H. Krentz, and T. Bucher. Uber lization of triglycerides or ketone bodies formed Metabolitgehalte und Metabolit-konzentrationen in in the liver at an increased rate as a result of der Leber der Ratte. Biochem. Z. 1959, 332, 18. more rapid hepatic uptake of FFA. In addition, 16. Armstrong, D. T., R. Steele, N. Altszuler, A. Dunn, the increase in oxygen consumption associated J. S. Bishop, and R. C. De Bodo. Regulation of with an increased turnover of fatty acids within plasma free fatty acid turnover. Amer. J. Physiol. the adipose tissue, as previously described, may 1961, 201, 9. 17. Borgstrom, B. Investigation on lipid separation contribute to the increase in over-all metabolic methods. Separation of phospholipids from neu- rate. tral fat and fatty acids. Acta physiol. scand. 1952, References 25, 101. 1. Griffith, F. R., Jr. Fact and theory regarding the 18. Steinberg, D. A new approach to radioassay of calorigenic action of adrenaline. Physiol. Rev. aqueous solutions in the liquid scintillation spec- 1951, 31, 151. trometer. Analyt. Biochem. 1960, 1, 23. 2. Ellis, S. The metabolic effects of epinephrine and 19. Thibault, 0. Adrenaline et sympathine. Action de related amines. Pharmacol. Rev. 1956, 8, 485. la nor-adrenaline sur la consommation d'oxygene 3. Fredrickson, D. S., and R. S. Gordon, Jr. Trans- du rat blanc. C. R. Soc. Biol. (Paris) 1948, 142, port of fatty acids. Physiol. Rev. 1958, 38, 585. 47. 4. Fritz, I. B., D. G. Davis, R. H. Holtrop, and H. 20. Lundholm, L. The effect of 1-noradrenaline and Dundee. Fatty acid oxidation by skeletal muscle ergotamine on the oxygen consumption of guinea during rest and activity. Amer. J. Physiol. 1958, pigs. Acta physiol. scand. 1949, 18, 341. 194, 379. 21. Lundholm, L. The effect of 1-noradrenaline on the 5. Eaton, P., and D. Steinberg. Effects of medium oxygen consumption and lactic acid content of the fatty acid concentration, epinephrine, and glu- blood in the rabbit. Acta physiol. scand. 1950, 21, cose on palmitate-1-C"4 oxidation and incorpora- 195. tion into neutral lipids by skeletal muscle in vitro. 22. Bauer, G., and F. Lembeck. Die stoffwechselstei- J. Lipid Res. 1961, 2, 376. gernde Wirkung des Noradrenalins. Naunyn- 6. Rose, H., M. Vaughan, and D. Steinberg. Utiliza- Schmiedeberg's Arch. exp. Path. Pharmak. 1951- tion of fatty acids by liver slices as a function 52, 214, 262. of medium concentration. Amer. J. Physiol. 1964, 23. Brewster, W. R., Jr., J. P. Issacs, P. F. Osgood, 206, in press. and T. L. King. The hemodynamic and metabolic 7. Nestel, P. J., and D. Steinberg. Fate of palmitate interrelationships in the activity of epinephrine, and of linoleate perfused through the isolated rat norepinephrine, and the thyroid hormones. Cir- liver at high concentration. J. Lipid Res. 1963, 4, culation 1956, 13, 1. 461. 24. Kroneberg, G., and G. Ronicke. Versuche mit Ar- 8. Black, J. W., and J. S. Stephenson. Pharmacology terenol am Menschen. Klin. Wschr. 1950, 28, of a new adrenergic beta-receptor-blocking com- 353. pound (Nethalide). Lancet 1962, 2, 311. de F. 9. Dornhorst, A. C., and B. F. Robinson. Clinical 25. Goldenberg, M., K. L. Pines, E. Baldwin, pharmacology of a beta-adrenergic-blocking agent D. G. Greene, and C. E. Roh. The hemodynamic (Nethalide). Lancet 1962, 2, 314. response of man to norepinephrine and epinephrine 10. Pilkington, T. R. E., R. D. Lowe, B. F. Robinson, and its relation to the problems of hypertension. and E. Titterington. Effect of adrenergic block- Amer. J. Med. 1948, 5, 792. 176 STEINBERG, NESTEL, BUSKIRK, AND THOMPSON

26. Reale, A., A. Kappert, C. H. Skoglund, and G. C. tors affecting fat mobilization from adipose tissue. Sutton. The effect of L-noradrenaline on the Amer. J. clin. Nutr. 1960, 8, 705. oxygen consumption of human beings. Acta 35. Mallov, S. Cold effects in rat: plasma and adipose physiol. scand. 1950, 20, 1953. tissue free fatty acids and adipose lipase. Amer. 27. Becker, J., A. Bernsmeier, and W. Lorenz. Unter- J. Physiol. 1963, 204, 157. suchungen uber den respiratorischen Stoffwechsel 36. Depocas, F. Calorigenesis from various organ sys- des Menschen unter der Wirkung von Noradren- tems in the whole animal. Fed. Proc. 1960, 19, alin. Z. ges. exp. Med. 1952, 119, 617. 19. 28. Whelan, R. F., and I. M. Young. The effect of 37. Hannon, J. P., and A. M. Larson. Fatty acid me- adrenaline and noradrenaline infusions on res- tabolism during norepinephrine-induced thermo- piration in man. Brit. J. Pharmacol. 1953, 8, 98. genesis in the cold-acclimatized rat. Amer. J. 29. Steinberg, D., R. P. Eaton, E. R. Buskirk, and R. H. Physiol. 1962, 203, 1055. Thompson. Unpublished data. 38. Havel, R. J., J. M. Felts, and C. M. Van Duyne. 30. Fredrickson, D. S., and R. S. Gordon, Jr. The Formation and fate of endogenous triglycerides in metabolism of albumin-bound C4-labeled unes- blood plasma of rabbits. J. Lipid Res. 1962, 3, terified fatty acids in normal human subjects. J. 297. clin. Invest. 1958, 37, 1504. 39. Gidez, L. I., P. S. Roheim, and H. A. Eder. Effect 31. Cori, C. F., and G. T. Cori. The mechanism of epi- of plasma free fatty acid concentrations on tri- nephrine action. II. The influence of epinephrine glyceride synthesis by the perfused liver. Fed. and insulin on the carbohydrate metabolism of rats Proc. 1962, 21, 289. in the postabsorptive state. J. biol. Chem. 1928, 40. Steinberg, D., R. P. Eaton, and S. Chernick. Un- 79, 321. published results. 32. Carlson, L. D. Nonshivering thermogenesis and its 41. Ball, E. G., and R. L. Jungas. On the action of endocrine control. Fed. Proc. 1960, 19, 25. hormones which accelerate the rate of oxygen 33. Hsieh, A. C. L., and L. D. Carlson. Role of adren- consumption and fatty acid release in rat adipose aline and noradrenaline in chemical regulation tissue in vitro. Proc. nat. Acad. Sci. (Wash.) of heat production. Amer. J. Physiol. 1957, 190, 1961, 47, 932. 243. 42. Levine, H. J., and R. J. Wagman. Energetics of 34. Wertheimer, E., M. Hamosh, and E. Shafrir. Fac- the human heart. Amer. J. Cardiol. 1962, 9, 372.

ANNOUNCEMENT OF MEETINGS The American Federation for Clinical Research will hold its Twenty-first Annual Meeting in Atlantic City, N. J., at the Casino Theater on the Steel Pier on Sunday, May 3, 1964, at 9:00 a.m. Joint sectional meetings with The American Society for Clinical Investigation will be held on Sunday afternoon at Chalfonte-Haddon Hall, and additional meetings sponsored by The American Federation for Clinical Research will be held on Sunday evening. The American Society for Clinical Investigation, Inc., will hold its Fifty-sixth Annual Meeting in Atlantic City, N. J., on Monday, May 4, at 9:00 a.m., at the Casino Theater on the Steel Pier, and in simultaneous programs with The American Federation for Clinical Research on Sunday afternoon, May 3, in Chalfonte-Haddon Hall. The Association of American Physicians will hold its Seventy- seventh Annual Meeting in Atlantic City, N. J., at the Casino Theater on the Steel Pier on Tuesday, May 5. at 9:30 a.m., and in the Vernon Room, Chalfonte-Haddon Hall, on Wednesday, May 6, at 9:30 a.m. The American Society for Clinical Nutrition will hold its Fourth Annual Meeting in Atlantic City, N. J., at the Colton Manor Hotel on Saturday, May 2, from 1 :00 to 5:00 p.m.