Androgen metabolism by rat epididymis. 2. Metabolic conversion of 3H-testosterone in vitro

The epididymis of adult rats metabolizes ³H-testosterone by experiments $\text{in}$$\text{vitro}$. After incubation of slices from epididymal tissue for 2 hrs at 37°C, 8% of the total radioactivity was found in the water-soluble fraction, whereas 92% in the ether soluble fraction (free steroids). The free steroids were examined further and the following metabolites identified: $\text{testosterone}$ (17β-hydroxy-4-androsten-3-one) 10,4%, $\text{androstendione}$ (4-androstene-3,17-dione) 6,2%, $\text{5α-A-dione}$ (5α-androstane-3,17-dione) 7,3%, $\text{DHT}$ (17β-hydroxy-5α-androstane-3-one) 39,3%, $\text{3α-diol}$ (5α-androstane-3α,17β-diol) 22,7%, $\text{3β-diol}$ (5α-androstane-3β,17β-diol) 4,6% and androsterone(3α-hydroxy-5α-androstan-17-one) 8,9%. The relative amount of each metabolite is given in per cent of the total radioactivity in the ether soluble fraction. When segments (caput, corpus, cauda) of epididymis were incubated in the same way, differences in steroid metabolism were demonstrated. Characteristic for caput epididymidis was high formation of DHT (58,4%) and 3α-diol (23,5%). Corpus epididymidis showed lower formation of DHT (50,6%) and 3α-diol (12,7%), but an approximately 3 times higher formation of 5α-A-dione (12,0%) than caput (3,4%) and cauda (3,5%). Cauda epididymis showed the lowest formation of DHT (38,3%), whereas 3α-diol (29,1%) and androsterone (11,4%) formation were relatively high. The ratio between 17β-hydroxy metabolites (DHT and androstanediols) and 17-keto metabolites were much higher in the caput (8,8) than in the corpus (3,2) and cauda (3,6), indicating a higher 5α-reductase activity in this segment.     

Androgen metabolism by rat epididymis: 5. Metabolic conversion and nuclear binding after injection of 5α-androstane-3α,17β-diol, in vivo

The pattern of androgenic metabolites in blood, muscle, caput and cauda epididymidis has been investigated in functionally hepatectomized 24 hours castrated rats, 3 hours after the intra-muscular injection of 200 μCi of ³H -3α-diol. Identification of the radioactive metabolites showed only negligible differences between the epididymal regions. In both caput and cauda the main metabolite was DHT (17β-hydroxy-5α-androstane-3-one); 3α- and 3β-diol, androsterone (3α-hydroxy-5α-androstane-17-one), 5-A-dione (5α-androstane-3,17-dione), Δ¹⁶-3α-ol (5α-androst-l6-en-3α-ol), Δ¹⁶-3β-ol (5α-androst-l6-en-3α-ol) and Δ¹⁶-3-one (5α-androst-l6-en-3-one) were also present.$\text{Androsterone}$ and $\text{3α-diol}$ were the predominant metabolites in blood and muscle. No Δ¹⁶ compounds could be detected and in constrast to epididymis, more than 50% of the radioactivity was associated with polar compounds. From determination of total radioactivity, it was seen that retention by epididymis varied from two to four times that of muscle. Purification and identification of the radioactivity associated with the nuclear fraction demonstrated that DHT was the only nuclear bound androgen.It is suggested from these results that at least one effect of 3α-diol on the rat epididymis is exerted through its conversion to DHT.     

Sertoli cells from immature rats : in vitro stimulation of steroid metabolism by FSH.

Sertoli cells from 10 day old rats convert androstenedione to testosterone and 5α-androstane-3α,17β-diol, testosterone to 17β-hydroxy-5α-androstan-3-one and 5α-androstane-3α,17β-diol, and 17β-hydroxy-5α-androstan-3-one to 5α-andro-stane-3α,17β-diol after 72 hours $\text{in vitro}$. Conversions of androstenedione to testosterone and 5α-androstane-3α,17β-diol, and testosterone to 5α-androstane-3α,17β-diol were 2 to 3 times greater in FSH treated cultures. Steroid conversion was not stimulated significantly by LH or TSH. The results are interpreted as evidence that in young rats Sertoli steroid metabolism is stimulated by FSH, that Sertoli cells are an androgen target and that FSH may induce or facilitate Sertoli androgen responsiveness.     

Reactions of 4β,5-epoxy-5β-androstan-3-ones with hydrogen fluoride in pyridine

4β,5-Epoxy-5β-androstane-3,17-dione ($\text{1a}$), 17β-hydroxy-4β,5-epoxy-5β-androstan-3-one ($\text{1b}$) and 17β-acetoxy-4β,5-epoxy-5β-androstan-3-one ($\text{1c}$) were treated with anhydrous hydrogen fluoride in pyridine (70% solution) at 55° and yielded the corresponding 4-en-4-ols e.g. 4-hydroxy-4-androstene-3, 17-dione ($\text{2a}$).As the reaction temperature was lowered each epoxide formed a second product which, at ?75°, was the major component of the reaction mixture and was identified as the 5α-fluoro-4α-ol derivative of the parent enone, e.g. 4α-hydroxy-5-fluoro-5α-androstane-3,17-dione ($\text{3a}$). These fluorohydrins are thermally unstable, losing hydrogen fluoride.The acetates of the fluorohydrins were also prepared, characterized, and shown to be more stable than the parent alcohols.     

Synthesis of 5α-Androstane-3α,16α,17β-triol from 3β-hydroxy-5-androsten-17-one

5α-Androstane-3α, 16α 17β-triol was synthesized from 3β-hy-droxy-5-androsten-17-one. The procedure Involved catalytic hydrogenation of 3β-hydroxy-5-androsten-17-one to 3β-hydroxy-5α-androstan-17-one. This was followed by conversion of the 3β-hydroxy group to 3α-benzoyloxy group by the Mitsunobu reaction. Further treatment with isopropenyl acetate yielded 5α-androsten-16-ene-3α, 17-diol 3-benzoate 17-acetate. This was then converted to 3α, 17-dihydroxy-5α-androstan-16-one 3-benzoate 17-acetate via the unstable epoxide intermediate after treatment with $\text{m}$-cloroperoxybenzoic acid. LiAlH₄ reduction of this compound formed 5α-androstane-3α, 16α, 17β-trlol. ¹H and ¹³C NMR of various steroids are presented to confirm the structure of this compound.     

Synthesis and pyrogenic effect of 3α,7α-dihydroxy-5β-androstan-17-one and 3α-hydroxy-5β-androstane-7,17-dione

The first chemical synthesis of 3α,7α-dihydroxy-5β-androstan-17-one and 3α-hydroxy-5β-androstane-7,17-dione is reported. In this method, the 17β-side chain of commercial chenodesoxycholic acid was degraded in 6 steps after selective protection of the hydroxyl groups : 3α-OH by a $\text{tert}$-butyldimetfaylsilyl group and 7α-OH by an acetoxy group. The capacity of 3α,7α-dihydroxy-5β-androstan-17-one and 3α-hydroxy-5β-androstane-7, 17-dione to release a pyrogen by human leukocytes was investigated by two independent methods : supernatants from leukocytes incubated with a steroid are injected to rabbits whose fever is measured, or tested by the Limulus Test (a pyrogen detection technique). The 7-keto substituted etiocholanolone still possessed pyrogenic activity, while the 7α-hydroxyl substituted one did not.     

In vitro conversion of testosterone-4-14C to androgens of the 5alpha-androstane series by a normal human ovary

In a previous communication (1) the identification of Δ⁴ -3-oxo-steroids and estrogens as metabolites of testosterone-4-¹⁴C incubated with normal post-ovulatory human ovaries was reported. Thin-layer chromatography of the extracts of those ovaries which contained no corpus luteum yielded zones of radioactivity which were not associated with any of these products. Detailed investigation of these zones from the extract of one of these glands resulted in identification of the following radiometabolites of the 5α-androstane series: 5α-androstane-3,17-dione, androsterone, 3β-hydroxy-5α-androstan-17-one, 17β-hydroxy-5α-androstan-3-one, 5α-androstane-3ga, 17β-diol and 5α-androstane-3β, 17β-diol. The capacity of a normal human ovary to produce these 5α-reduced androgens, especially the potent 17β-hydroxy-steroids, suggests a regulatory role of these compounds in ovarian function.     

Steroid metabolism by mouse submaxillary glands. I. in vitro metabolism of testosterone and 4-androstene-3,17-dione

Tritiated 4-androstene-3,17-dione and testosterone were incubated with submaxillary gland homogenates of 6 month old male mice. In 15 and 180 minute incubations fortified with NADPH, submaxillary tissue converted 4-androstene-3,17-dione predominantly to androsterone and, to a lesser extent, testosterone, 17β-hydroxy-5α-androstan-3-one and 5α-androstane-3α, 17β-diol. Testosterone was converted primarily to 5α-androstane-3α, 17β-diol when exogenous NADPH was available; trace amounts of 4-androstene-3,17-dione, 17β-hydroxy-5α-androstan-3-one and androsterone were also formed. When a NADPH-generating system was omitted from the incubation medium both 4-androstene-3,17-dione and testosterone were poorly metabolized by submaxillary tissue; the amounts of reduced metabolites accumulating were markedly reduced.     

Androgen metabolism by rat epididymis 4. The formation of conjugates

The ability to form androgen conjugates and the hormone dependency of the conjugating enzymes have been studied in the rat epididymis.Following the in vitro incubation of ³H-testosterone with epididymal slices from intact and castrated rats, the radioactivity recovered was partitioned between water and ether. Examination of the water soluble radioactivity demonstrated the presence of glucuronides and sulfates. The total radioactivity in the conjugate fraction was the same for both intact and castrated animals. However, castrated rats showed a 3-fold increase in the glucuronide fraction with a corresponding decrease in the formation of sulfates. Characterization of the ether soluble radioactivity after solvolysis of the conjugate fraction from castrated animals, showed DHT (17β-hydroxy-5α-androstan-3-one) and 3α-diol (5α-androstane-3α,17β-diol) to be the main metabolites. After β-glucuronidase hydrolysis of the same, only 3α-diol could be demonstrated at a significant level, although traces of DHT and δ¹⁶ compounds were present.Corresponding hydrolysis of the water phase from incubation of epididymis from intact rats, demonstrated a marked quantitative difference. Here approximately 40% of the conjugated aglycones consisted of Δ¹⁶ compounds, whilst only abot 12% was comprised of 3α-diol. The preferential conjugation of DHT and 3α-diol to a sulfate radical was demonstrated in both intact and castrated rats. Since the conjugated Δ¹⁶ compounds were detected only in the epididymis from intact animals, it is possible that these are formed by the spermatozoa.     

Androgen regulation of progestin biosynthetic enzymes in FSH-treated rat granulosa cells in vitro

The influence of androgens on the FSH modulation of progestin biosynthetic enzymes was studied $\text{in vitro}$. Granulosa cells obtained from immature, hypophysectomized, estrogen-treated rats were cultured for 3 days in a serum-free medium containing FSH (20 ng/ml) with or without increasing concentrations (10^?9?10^?6 M) of 17β-hydroxy-5α-androstan-3-one (dihydrotestosterone; DHT), 5α-androstane-3α, 17β-diol (3α-diol), or the synthetic androgen 17β-hydroxy-17-methyl-4,9,11-estratrien-3-one (methyltrienolone; R1881). FSH treatment increased progesterone and 20α-hydroxy-4-pregnen-3-one(20α-OH-P) production by 10.2- and 11-fold, respectively. Concurrent androgen treatment augmented FSH-stimulated progesterone and 20α-OH-P production in a dose-related manner (R1881 > 3α-diol > DHT). In the presence of an inhibitor of 3β-hydroxysteroid dehydrogenase (3β-HSD), the FSH-stimulated pregnenolone (3β-hydroxy-5-pregnen-20-one) production (a 20-fold increase) was further enhanced by co-treatment with R1881, 3α-diol or DHT. Furthermore, FSH treatment increased 4.4-fold the activity of 3β-HSD, which converts pregnenolone to progesterone. This stimulatory action of FSH was further augmented by concurrent androgen treatment. In contrast, androgen treatment did not affect FSH-stimulated activity of a progesterone breakdown enzyme, 20α-hydroxysteroid dehydrogenase(20α-HSD). These results demonstrate that the augmenting effect of androgens upon FSH-stimulated progesterone biosynthesis is not due to changes in the conversion of progesterone to 20α-OH-P, but involves an enhancing action upon 3β-HSDΔ⁵, Δ⁴-isomerase complexes and additional enzymes prior to pregnenolone biosynthesis.     

Proton magnetic resonance spectra of 17ξ-Hydroxy-17ξ-methyl-5ξ-androstane C-3 ketone and c-3ξ alcohol isomers in chloroform-d and pyridine-d5

17α-Hydroxy-17β-methyl-5β-androstan-3-one, 17μ-methyl-5α-androstane-3α, 17α-diol, 17β-methyl-5α-androstane-3β, 17α-diol, 17α-methyl-5β-androstane-3β, 17β-diol, 17β-methyl-5β-androstane-3α, 17α-diol and 17β-methy1–5β-androstane-3β, 17α-diol were synthesized for the first time. ¹H NMR spectra of all four 17ξ-hydroxy/17ξ-methyl C-3 ketones and all eight C-3 alcohols were recorded in chloroform-d and pyridine-d₅. Pyridine-induced chemical shifts are discussed. Thin-layer Chromatographic data are given.     

Metabolism of 17β-hydroxy-2-hydroxymethylene-5α-androstan-3-one in the rabbit

An acidic metabolite, 2α-carboxy-5α-androstane-3α, 16α, 17αtriol and two neutral metabolites, 2α-hydroxymethyl-5α-androstane-3α, 17α-diol, and 2α-hydroxymethyl-5α-androstane-3α, 16α, 17α-triol have been identified in the urine of rabbits orally dosed with 17β-hydroxy-2-hydroxymethylene-5α-androstan-3-one. 2α-Hydroxymethyl-5α-androstane-3α, 16α, 17α-triol was previously obtained from the urine of rabbits dosed with 17β-hydroxy-2α-methyl-5α-androstan-3-one. The acidic metabolite was the major urinary excretion product.     

Biotransformation of testosterone and other androgens by suspension cultures of Nicotiana tabacum “Bright yellow”

It has been shown that the cultured cells of Nicotiana tabacum “Bright Yellow” are capable of transforming testosterone to Δ⁴-androstene-3, 17-dione, 5α-androstan-17β-ol-3-one, 5α-androstane-3β, 17β-diol, its dipalmitate and 3- and 17-monoglucosides, epiandrosterone, its palmitate and glucoside, testosterone glucoside. 5α-Androstane-3β, 17β-diol dipalmitate and 3- and 17-monoglucosides, epiandrosterone palmitate and glucoside, and testosterone glucoside have been found for the first time as metabolites of testosterone in plant systems. Δ⁴-Androstene-3,17-dione was converted to testosterone. 5α-Androstan-17β-ol-3-one, which has been recognized as an active form of testosterone in mammals, was also detected. It has also been demonstrated that [4-¹⁴C]testosterone is actively incorporated in these transformations.     

The identification and characterization of the c19o3 steroid metabolites of 5α-androstane-3β, 17β-diol produced by the canine prostate: 5α-androstane-3β, 6α, 17β-triol and 5α-androstane-3β, 7α, 17β-triol

This study has identified the polar metabolites of 5α-androstane-3β, 17β-diol(3β-diol) produced by the canine prostate. The major metabolite is 5α-androstane-3β, 7α, 17β-triol (7α-triol) accounting for approximately 80% of the total polar metabolites of 3β-diol. The remaining 20% is accounted for exclusively by another triol, 5α-androstane-3β, 6α, 17β-triol(6α-triol). This study has also characterized two enzymatic hydroxylases responsible for respective triol formation: 5α-androstane-3β, 17β-diol 6α-hydroxylase (6α-hydroxylase) and 5α-androstane-3β, 17β-diol 7α-hydroxylase (7α-hydroxylase). Both of these irreversible hydroxylases are located in the particulate fraction of the prostate and can utilize either NADH or NADPH as cofactor. Several $\text{in vitro}$ steroid inhibitors of these hydroxylases were identified including cholesterol, estradiol and diethylstilbestrol. Neither of the hydroxylases were found to be decreased by castration (3 months) when expressed as activity/DNA. Using a variety of C₁₉ androstane substrates, 6α- and 7α-triol were found to be major components of the total 3β-hydroxy-5α-androstane metabolites produced by the canine prostate.     

Testosterone metabolism by isolated human axillary corynebacterium spp.: A gaschromatographic mass-spectrometric study

Transformations of [4-¹⁴C]testosterone have been studied in Corynebacterium spp. isolated from the axillae of men. Metabolites have been separated by TLC and capillary gas chromatography and have been identified by gas chromatography-mass spectrometry (GC-MS). The introduction of a clean-up step using Florisil columns, prior to TLC, removed Tween-80 which co-extracted from the medium with the metabolites. This procedure greatly improved TLC resolution.Testosterone was converted enzymically to 5α- and 5β-DHT, identification being assisted by the inclusion of [3,4-¹³C]testosterone in some incubations. Other metabolites formed enzymically were 4-androstene-3,17-dione, 5β-androstane-3,17-dione, 3β-hydroxy-5β-androstan-17-one and 5β-androstane-3α.l7α-diol. Some spontaneous breakdown of [¹⁴C]testosterone occurred giving rise to 5α(β)-DHT, androstanediol and a monohydroxy-diketo-androstene, the latter being reduced enzymically to 2 monohydroxy-diketo-androstanes. Under the conditions used, no clear evidence has been obtained for the formation of 5α-androst-16-en-3-one, an odorous steroid that occurs in the axillae of men; the possible reasons why we were unable to prove the biosynthesis of this compound are discussed.     

In vitro conversion of 5alpha-reduced metabolites of testosterone by the seminal vesicles, ventral prostate glands and testes of adult rats

In order to ascertain the ability of rat seminal vesicles, testes and ventral prostate glands to interconvert 5α-reduced androgens, these three organs were incubated with either tritiated 17β-hydroxy-5αandrostan-3-one (5α-dihydrotestosterone,DHT), 5α-androstane-3α, 17βdiol (3α-diol) or 5α-androstane-3β, 17β-diol (3β-diol). The incubation environment utilized (Krebs-Ringer bicarbonate glucose buffer) was selected because the histologic appearance of the tissue at the conclusion of the incubation was indistinguishable from tissue fixed immediately after sacrifice of the animal, thereby approximating the physiologic conditions as closely as possible. In incubations of rat seminal vesicles, ³H.-3β-diol was not metabolized while 26.7 ± 3.8% of ³H-3α-diol appeared as DHT and 17.2 ± 1.5% of ³H-DHT was metabolized to 3α-diol. A small amount (7.5 ± 0.8%) of ³H-DHT was, however, converted to 3β-diol. In incubations of rat testes, the major metabolite, regardless of substrate, was 3α-diol. The conversion of 75.7 ± 2.1% of ³H-3β-diol to 3α-diol has demonstrated, for the first time, that this steroid can be metabolized by the rat testis. Rat ventral prostate glands metabolized $\text{18.5 ± 2.5\%}\text{of}{}^3\text{H-3β-}\text{diol}$ to DHT and 61± 2.9% of ³H-3α-diol to DHT. When ³H-DHT served as the substrate, 83.2 ± 1.5% remained unmetabolized. The prostate glands are, therefore, capable of metabolizing 3β-diol to DHT.     

An analysis of the metabolites of progesterone produced by isolated sertoli cells at the onset of gametogenesis

Sertoli cells isolated from 17 day old rats were maintained in culture and incubated with [¹⁴C]-progesterone for 20 h. The cells and media were extracted with ether/chloroform and the extracts chromatographed two-dimensionally on TLC and the radioactive metabolites visualized by autoradiography. Nine of the metabolites (constituting about 88% of total metabolite radioactivity) were identified by relative mobilities of the compounds and their derivatives in TLC and GC systems and by recrystallizations with authentic steroids as the following: 20α-hydroxypregn-4-en-3-one, 3α-hydroxy-5α-pregnan-20-one, 5α-pregnane3α,20α-diol, 17β-hydroxy-5α-androstan-3-one, 5α-pregnane-3,20-dione, 17-hydroxypregn-4-ene-3,20-dione, testosterone, 5α-androstane-3α,17β-diol and androst-4-ene-3,17-dione. Over 71% of the metabolite radioactivity was due to 20α-hydroxypregn-4-en-3-one, the major metabolite. 5α-reduced pregnanes constituted about 12% and C₁₉ steroids comprised about 2.9% of the radioactivity of the metabolites. Calculation of relative steroidogenic enzyme activities from initial reaction rates suggested the following activities in μunits/mg Sertoli cell protein: 20α-hydroxysteroid oxidoreductase (20α-HS0; 7.71), 5α-reductase (4.77), 3α-HS0 (3.57), 17α-hydroxylase (0.93), 17β-HS0 (0.34) and C₁₇-C₂₀ lyase (0.34). The relatively high rate of steroidogenic enzyme activities in the Sertoli cells of young rats may indicate that Sertoli cells are less dependent on Leydig cell steroidogenesis than has been assumed. Since nearly all the metabolites of progesterone and testosterone are now identified, it is possible to construct a picture of Sertoli cell steroidogenic activity.     

Acetylation and hydroxylation of 5alpha-androstane-3beta,17beta-diol by prostate and epididymis

An unknown radiometabolite, formed in the canine prostate and epididymis after intra-arterial infusion of testosterone-4-¹⁴C in physiologic saline and extraction of the organs with ethyl acetate-acetone, was identified as the 3-monoacetate of 5α-androstane-3β, 17β-diol (3β-diol). Transformation of 3β-diol-¹⁴C to its identified 3-monoacetate derivative could also be demonstrated, if the incubation of the radiosubstrate with minced canine prostate was terminated by ethyl acetate extraction. The formation of polar products in high yield was noted. Whereas minced canine prostate actively converted 5α-androstane-3α,17β-diol-¹⁴C to 17β-hydroxy-5α-androstan-3-one-¹⁴C, the same preparation hydroxylated 3β-diol-¹⁴C predominantly at the 7ξ- and, to a lesser extent, at the 6ξ-positions. Partial identification of the hydroxylated radiometabolites was by crystallization of the CrO₃-oxidation products 5α-androstane-3,6,17-trione-¹⁴C and 5α-androstane-3,7,17-trione-¹⁴C to constant SA and by GLC/MS of the latter derivative. NADPH-supplementation of the preparation enhanced the yield of hydroxylated products derived from 3β-diol-¹⁴C in a 1 hr incubation from 22% to 41%. Analogous supplemented incubations of benign hyperplastic human prostate and canine epididymis produced polar metabolites (in 12.5% and 76% yields, respectively) which gave rise to similar proportions of the same androstanetrione epimers on CrO₃-oxidation.     

Biotransformation studies of prednisone using human intestinal bacteria Part II: Anaerobic incubation and docking studies

Anaerobic incubation of prednisone 1 with human intestinal bacteria (HIB) afforded nine metabolites: 5β-androst-1-ene-3,11,17-trione 3, 3α-hydroxy-5α-androstane-11,17-dione 4, 3β,17α,20-trihydroxy-5α-pregnan-11-one 5, 3α,17α-dihydroxy-5α-pregnane-11,20-dione 6, 3α,17α-dihydroxy-5β-pregnane-11,20-dione 7, 3β,17β-dihydroxy-5α-androstan-11-one 8β, 3β,17α-dihydroxy-5α-androstan-11-one 8α, 3α,17β-dihydroxy-5α-androstan-11-one 9β, and 3α,17α-dihydroxy-5α-androstan-11-one 9α. The structures of these metabolites (3–9) were elucidated using several spectroscopic techniques. Computer-aided prediction of potential biological activities of the isolated prednisone metabolites (3–9) revealed potential inhibition of prostaglandin E2 9-ketoreductase (PGE2 9-KR). Docking studies applied to PGE2 9-KR allowed recommendation of the metabolites 4, 8β, and 8α for further pharmacological study as PGE2 9-KR inhibitors.     

The synthesis of 17-substituted 2α-chloro-5α-androstan-3-ols

This paper describes the synthesis of 2α-chloro-3α-hydroxy-5α-androstan-17-one and 2α-chloro-5α-androstane-3α,17β-diol and their 3-epimers. The epimers were characterized by nmr spectroscopy.