The Metabolism of Corticosterone in Man
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THE METABOLISM OF CORTICOSTERONE IN MAN Ralph E. Peterson, Charles E. Pierce J Clin Invest. 1960;39(5):741-757. https://doi.org/10.1172/JCI104091. Research Article Find the latest version: https://jci.me/104091/pdf THE METABOLISM OF CORTICOSTERONE IN MAN By RALPH E. PETERSON * AND CHARLES E. PIERCE * (From the National Institute of Arthritis and Metabolic Diseases, National Institutes of Health, Bethesda, Md.) (Submitted for publication November 5, 1959; accepted December 4, 1959) Corticosterone was the first biologically active MATERIALS AND METHODS to be isolated from adrenal gland ex- hormone Seventeen normal subj ects, one bilaterally adrenalec- tracts (1, 2). Although contributing little to the tomized subject, and patients with cirrhosis, myxedema, body pool of adrenocortical steroids in man, it is and thyrotoxicosis were studied. one of the major adrenocortical secretory products Corticosterone was prepared for intravenous adminis- in some animals, e.g., rodents (3). In man the tration by dissolving 50, 100 or 200 mg of the crystalline is cortisol and the ma- steroid in 10 to 15 ml ethanol, which was added to 300 major glucocorticosteroid ml sterile 5 per cent dextrose in water. The solution jor mineralocorticosteroid is probably aldosterone; was infused over a period of 10 to 20 minutes. The nevertheless, corticosterone has been identified orally administered corticosterone was suspended in and measured in human adrenal tissue (4), saline or given in a gelatin capsule. Corticosterone-4-C"4 adrenal gland perfusates (5), adrenal vein blood (0.004 ,uc per ,g) was administered intravenously in (6-8), and peripheral blood (9-16). In all of trace quantities (100 to 400 ,ug) in a small volume of 5 per cent ethanol in sterile distilled water over a period these tissues the corticosterone concentration was of 5 minutes. Corticosterone-HW (1.5 utc per lAg) was found to be lower than that of cortisol, although administered in trace quantities (7 to 30 ,ug) in a small the concentration of the biologically important volume of 5 per cent ethanol in sterile distilled water. aldosterone has been found to be even less than After injection of the steroids, heparinized blood samples of the corticosterone (17, 18). were collected at 20 to 30 minute intervals. that The extraction procedures for the plasma cortico- Unlike cortisol, little is known about the rates sterone were similar to those described previously for of secretion of corticosterone in the normal sub- cortisol (19). Following the infusion of the pharma- ject, or its alteration in disease. This paucity of calogical quantities of the steroid, two different methods knowledge stems largely from the fact that there were used to determine the plasma corticosterone con- are no or semi- centration. readily available quantitative Fluorometric assay. Five-tenths ml plasma was ex- quantitative methods for determining even a tracted with 5 ml dichloromethane [purified by passage single fraction of the metabolites of corticosterone through a column of silica gel (21)]. The plasma was in the urine. removed by aspiration, and the dichloromethane extract In previous reports we have described studies on the physiological disposition and metabolic fate 21-trihydroxy-1,4-pregnene-3,20-dione) ; 11-dehydrotetra- hydrocorticosterone (3a,21-dihydroxy-pregnane-11,20-di- of cortisol (19) and cortisone (20) in man. This one); 3a-allotetrahydrocorticosterone (3a,1 1p,21-trihy- paper describes similar studies with corticosterone droxy-allopregnane-20-one); 11-dehydroallotetrahydro- using corticosterone, corticosterone-4-C14, and H3- corticosterone (3a,21 -dihydroxy-allopregnane- 11,20 -di - labeled corticosterone.1 one); 11-dehydro-corticosterone (21-hydroxy-4-pregnene- 3-11,20-trione); 1 1-desoxycortisol (17a,21-dihydroxy- * Present address: Cornell University Medical Center, 4-pregnene-3,20-dione); 20a-hydroxycorticosterone (11,B,- Department of Medicine, New York 21, N. Y. 20a,21-trihydroxy-4-pregnene-3-one); 20j8-hydroxycorti- 1 In this paper the trivial names of the steroids have costerone (1 1fi,20,8,21-trihydroxy-4-pregnene-3-one); 11- been used: cortisol (1 lp,17a,21-trihydroxy-4-pregnene- epicorticosterone (1 la,21 -dihydroxy-4-pregnene-3,20-di- 3,20-dione); cortisone (17a,21-dihydroxy-4-pregnene-3,- one); allotetrahydrocortisol (3a,1 1,,17a,21-tetrahydroxy- 11,20-trione); corticosterone (11f,21-dihydroxy-4-preg- allopregnane-20-one); allotetrahydrocortisone (3a,17a,21- nene-3,20-dione); tetrahydrocortisone (3a,17a,21-trihy- trihydroxy-all pregnane-11, 20-dione); A1-9a-fluoro-16a- droxy-pregnane-11,20-dione); tetrahydrocortisol (3a,11X8,- hydroxycortisol diac (16a,21-diacetoxy-1 la,17a-dihydroxy- 17a,21 -tetrahydroxy-pregnane,20-one); tetrahydrocorti- 9a-fluoro-1,4 - pregnene - 3,20 - dione) ; 2a - methylcortisone costerone (3a,11p8,21-trihydroxy-pregnane-20-one); 9a- (2a-methyl-11,8,17a,21-trihydroxy-4-pregnene-3,20-dione); fluorocortisol (9ca-fluoro-11#,17a,21 -trihydroxy-4-preg- 20,8-hydroxycortisone (17a,208,21-trihydroxy-4-pregnene- nene-3,20-dione); A1-9a-fluorocortisol (9a-fluoro-1 l,,17a,- 3,1 1-dione). 741 742 RALPH E. PETERSON AND CHARLES E. PIERCE washed with 0.5 ml 0.1 N NaOH. Each of two 2 ml per cent (vol/vol) acetic anhydride-1-C" (2 mc per aliquots of the extract was transferred to a small conical mmole) in benzene and in pyridine for 24 hours at room test tube and shaken with 1 ml of a sulfuric acid-ethanol temperature. The unused acetic anhydride was removed (redistilled ethanol) reagent (65: 35 vol/vol). The by partitioning twice between a small volume of 20 per solvent was removed by aspiration and the acid-alcohol cent ethanol and dichloromethane. The aqueous layer reagent transferred to a small cuvet for fluorescence was removed by aspiration into an alkali trap. After determination in a Farrand fluorometer by a previously addition of 20 /Ag of corticosterone acetate, the dichloro- described modification (12) of the method of Sweat (22). methane was evaporated to dryness. The residue was Isotope dilution assay. The plasma samples were also chromatographed successively in the following systems: assayed for corticosterone by the isotope dilution proce- 1) cyclohexane 100: benzene 50: methanol 100: water dure as previously described (12), except that 5 ml of 25, 15 hours; 2) cyclohexane 100: dioxane 100: methanol plasma was used for each determination. Radioactivity 50: water 25, 18 hours; and 3) cyclohexane 100: benzene measurements were made in a Tri-Carb liquid scintilla- 50: methanol 100: water 25, 15 hours. After elution from tion spectrometer (Packard Instrument Co.). the second chromatographic purification and prior to the Determination of plasma corticosterone-H' and labeled third and final chromatography, the residue was oxidized imetabolites. The disappearance of HW-labeled cortico- to 11-dehydrocorticosterone acetate with 0.1 ml 0.5 per sterone from the plasma was determined by first adding cent CrO3 in redistilled glacial acetic acid. After ex- a known number of counts of corticosterone-4-C" (500 posure to the CrO3 for 1 minute at room temperature, cpm at an efficiency of 30 per cent) to a known volume 1 ml of 20 per cent ethanol-water was added and the of each plasma sample collected after the infusion of the steroid acetate was extracted with dichloromethane. The labeled steroid. The plasma was extracted with di- dichloromethane was evaporated to dryness and the resi- chloromethane and the residue chromatographed in a due applied to paper for the third chromatographic modified Bush-type system (23) (cyclohexane 100: ben- purification. zene 100: methanol 100: water 50) for 24 hours at room The 11-dehydrocorticosterone acetate was eluted into a temperature using unlabeled corticosterone (20 ,sg) as a counting vial, dried, and 5 ml toluene containing 0.4 per marker. The corticosterone was then located with ultra- cent DPO (diphenyloxazole) and 0.004 per cent POPOP violet light, eluted, and assayed for C" and H' in a [1,4-bis-2- (5-phenyloxazolyl) -benzene] phosphor added. liquid scintillation spectrometer. The C" in this case The samples were assayed for C" and H' in a liquid was used to correct for losses of corticosterone-H' dur- scintillation spectrometer. The calculations of the spe- ing the extraction, evaporation, chromatography, and cific activities have been described previously (24). elution steps. The mixtures of C" and H' were counted From a knowledge of the specific activity of the acetic by previously described methods (24). The combined anhydride-1-C" and the C" counts in the counting vial, plasma "free" corticosterone and its metabolites were it was possible to determine the micrograms of corticos- measured by direct counts of an aliquot of the dichloro- terone in the vial. From the counts of tritium and the methane extract of the plasma. The plasma radioactive micrograms of corticosterone in the vill, the specific metabolites of corticosterone conjugated with glucuronic activity of the corticosterone was determined. The frac- acid were determined by a previously described method tional rate of turnover of corticosterone and the miscible (19). pool size were determined as previously described for Determination of specific activity of labeled plasma cortisol (25). corticosterone. Fifteen to 20 ml of heparinized plasma Comparison of in vivo metabolism of H'- and C"-la- collected serially after injection of corticosterone-H' was beled corticosterone. A solution of 320 ,ug corticosterone extracted with 7 volumes of dichloromethane. The labeled with both H' and C" was injected into a normal plasma was removed by aspiration, and the dichloro- subject (N. K.) who was receiving a continuous intra- methane washed successively with 1/10 volume 0.1 N venous infusion of corticotropin (4 units per hour) for NaOH and 1/10 volume of 0.1 M acetic acid. The di- 36 hours. The labeled steroid was given 12 hours after chloromethane extract was evaporated to dryness.