[en] Some difference in functional pool of cholesterol acting as the precursor of bile acids is pointed out between cholic acid and chenodeoxycholic acid. In order to elucidate this problem further, some experiments were performed with rats equilibrated with [7(n)-³H, 4-¹⁴C] cholesterol by subcutaneous implantation. The bile duct was cannulated in one series of experiments and ligated in another. After the operation ¹⁴C-specific radioactivity of serum cholesterol fell, but reached practically a new equilibrium within three days. ¹⁴C-Specific radioactivity of serum cholesterol as well as of biliary bile acids in bile-fistula rats and urinary bile acids in bile duct-ligated rats was determined during a three days-period in the new equilibrated state. The results were as follows: (1) ¹⁴C-Specific radioactivity of cholic acid and chenodeoxycholic acid in bile was lower than that of serum cholesterol, and ¹⁴C-specific radioactivity of cholic acid was clearly lower than that of chenodeoxycholic acid. (2) ¹⁴C-Specific radioactivity of cholic acid and beta-muricholic acid in urine was lower than that of serum cholesterol, and ¹⁴C-specific radioactivity of cholic acid was lower than that of beta-muricholic acid. (3) Biliary as well as urinary beta-muricholic acid lost tritium label at 7-position entirely during the course of formation from [7(n)-³H, 4-¹⁴C]cholesterol

[en] The synthesis of 16 alpha-³H androgens and estrogens is described. 1-(³H)-Acetic acid in the presence of zinc dust reacts with 16 alpha-bromo-17-ketosteroids to produce 16 alpha-³H-17-ketosteroids. This chemical reaction was used to prepare 16 alpha-³H-dehydroepiandrosterone (I) and 16 alpha-₄H-estrone acetate (XI) from 16 alpha-bromo-dehydroepiandrosterone (X) and from 16 alpha-bromo-estrone acetate (XII), respectively. Using appropriate microbiological techniques, it was possible to convert these radiolabelled substrates into 16 alpha-³H-androstenedione (II) and 16 alpha-³H-estradiol-17 beta (VII). 16 alpha-³H-Estrone (VI) was obtained by the chemical hydrolysis of 16 alpha-³H-estrone acetate. The label distribution as determined by microbiological 16 alpha-hydroxylations indicated a specific labelling of 77% for androgens and 65% for estrogens in the 16 alpha position. These substrates can be used for measuring the 16 alpha hydroxylase activity, an important step in the biosynthesis of estriol (VIII) and estetrol

[en] The percutaneous absorption of ³H-promestriene (an antiseborrhoeic agent; 3-propoxy-17 beta-methoxy-1,3,5(10)-estratriene) was studied in rats and human subjects. Extensive and continual absorption of the tritium label (about 50% dose in 3 days) occurred in rats when the treated area of skin (ca. 30 micrograms/cm2) was occluded; when unabsorbed material was washed off after 6 h, a substantial proportion of the applied ³H (about 25% dose) had been absorbed to be excreted later. In contrast, less than 1% of the ³H applied to the skin of human volunteers (0.1-0.5 mg/cm2) was absorbed within 6 h and subsequently excreted. In rats, tissue concentrations of ³H were greatest in the liver, adrenals and ovaries

[en] Freshly ejaculated spermatozoa from monkey and human were washed and incubated with tritium labelled androgens or estradiol to study the pattern of spermatozoa steroid metabolism. When equal concentrations of steroid substrates were used for incubation, monkey and human spermatozoa showed very similar pattern of steroid conversion. Spermatozoa from both species converted testosterone mainly to androstenedione, but reverse conversion of androstenedione to testosterone was negligible. Estradiol-17 beta was converted mainly to estrone. The close similarity between the spermatozoa of monkey and men in their steroid metabolic pattern indicates that the rhesus monkey could be an useful animal model to study the effect of drugs on the metabolic pattern of human spermatozoa

[en] Preimplantation rabbit embryos were incubated with pregnenolone and dehydroisoandrosterone under conditions which gave formazan precipitation by the histochemical technique. The metabolic fate of the labeled steroids were assessed simultaneously. There was no concomitant transformation of pregnenolone to progesterone and dehydroisoandrosterone was not transformed to androstenedione. It is concluded that the formazan precipitation is coupled with an activity other than delta 5-3 beta-hydroxysteroid oxidoreductase

[en] After intramuscular administration of 16 beta-ethyl-17 beta-hydroxy-4-4-[4-¹⁴C]estren-3-one (¹⁴C-oxendolone; 300 mg) to 3 human subjects, excretion of ¹⁴C was very slow and incomplete despite a 20-day sample collection period. During this time, means of 37% and 21% of the administered ¹⁴C were recovered in urine and feces, respectively, and if excretion continued at the same rate, approximately 90% of the administered ¹⁴C would have been excreted during 5-12 weeks. Peak plasma ¹⁴C concentrations were reached at 3-6 days after dosing, when they represented 0.2-1.1 micrograms equiv./ml, and declined very slowly thereafter with a half-life of 5.0-6.6 days. Concentrations of unconjugated drug-related steroids circulating in plasma never exceeded about 0.1 microgram/ml. Mass spectroscopic analysis of isolated urinary and fecal metabolites indicated that the principal routes of biotransformation of oxendolone in man are similar to those of the endogenous androgens-namely, reduction of the 4,5-double bond, further reduction of the saturated 3-ketone to the 3 alpha-hydroxysteroid, and oxidation of the 17 beta-alcohol to the corresponding ketone, followed by conjugation, mainly with glucuronic acid, and excretion in the urine and bile

[en] A synthetic route for labelling 6 beta-(2'-fluoro)ethyl-19-norcholest-5(10)-en-3 beta-ol (VII) with fluorine-18 was developed to evaluate the potential utility of VII as an adrenal imaging agent. 6 beta-p-Toluene-sulphonyloxymethyl-19-norcholest-5(10)-en-3 beta-ol acetate (I) was converted to the 6 beta-(2'-hydroxy)ethyl (VI) in a five-step process. The treatment of VI with N-N-diethyl (2-chloro-1,1,2,-trifluoroethyl)amine in methylene chloride and subsequent hydrolysis with base gave the required VII. Iodination of VI with triphenoxymethylphosphonium iodide followed by alkaline hydrolysis gave the 6 beta-(2'-iodo)ethyl (IX) which, on treatment with silver fluoride in acetonitrile, furnished the 6 beta-(2'-fluoro)ethyl (VII). Excellent conversion of the 6-beta-(2'-p-toluenesulphonyloxy)-ethyl (X) into VII was also achieved by heating with potassium fluoride for 2 hr in diethylene glycol in 76% yield, which is a readily applicable method for labelling with fluorine-18

[en] The ability of Sertoli cells to metabolize ³H-estradiol-17 beta was investigated utilizing Sertoli cell cultures isolated from 18d rat testes. The Sertoli cells converted estradiol-17 beta to estriol as shown by recrystallization of estriol from samples containing cells and media but not from cell-free control media. The effect of FSH treatment on such metabolism was investigated and was shown to be similar to nontreated samples. This is the first demonstration that 16 alpha-hydroxylase is present in Sertoli cells and that this enzyme activity is not under the influence of FSH

[en] [3beta-3H]-bile acids and bile alcohols may be useful for metabolic studies in man and animals because the 3-position is invulnerable to bacterial attack. A number of tritium labeled bile acids and bile alcohols were prepared by selective oxidation of the hydroxyl group at carbon-3 followed by reduction with NaBT4. In each case, the bile acids and bile alcohols epimeric at carbon-3 were resolved by analytical and preparative thin-layer chromatography and characterized by gas liquid chromatography. The average yield was 60 to 65% and specific activities of the final products were in the range of 7.4 x 10⁷ dpm/mg

[en] Polar metabolites extracted from the effluents of viable porcine uterine strips superfused with either 6,7-3H-estrone or 6,7-3H-estradiol were identified as a 1:1 mixture of 6 alpha-hydroxyestrone and 7 alpha-hydroxyestrone by paper chromatography in various systems, derivatization and crystallizations to a constant specific activity. The hydroxylated compounds are the only derivatives detected after estrone superfusion. The major metabolite of estradiol released in short-time experiments is estrone followed by its 6 alpha- and 7 alpha-hydroxylated derivatives