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1.
The epididymis of adult rats metabolizes 3H-testosterone by experiments invitro. 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: testosterone (17β-hydroxy-4-androsten-3-one) 10,4%, androstendione (4-androstene-3,17-dione) 6,2%, 5α-A-dione (5α-androstane-3,17-dione) 7,3%, DHT (17β-hydroxy-5α-androstane-3-one) 39,3%, 3α-diol (5α-androstane-3α,17β-diol) 22,7%, 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.  相似文献   

2.
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.Androsterone and 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.  相似文献   

3.
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 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.  相似文献   

4.
P Ofner  R L Vena 《Steroids》1974,24(2):261-279
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.  相似文献   

5.
The activity of cholesterol 7α-hydroxylase in rat liver microsomes was assayed by measuring the mass of 5-cholestene-3β, 7α-diol formed from endogenous cholesterol under standardized incubation conditions. After termination of incubations, a known amount of 5-[24,25,7β-2H3]cholestene-3β,7α-diol was added. A chloroform extract of the incubation mixture was subjected to thin layer chromatography and the fraction containing 5-cholestene-3β,7α-diol was converted into trimethylsilyl ether. The trimethylsilyl ether was subjected to combined gas chromatography-mass spectrometry and the amount of unlabeled 5-cholestene-3β,7α-diol in the mixture was calculated from the ratio between the relative intensitics of the peaks at me 456 (M-90) and me 459 [M-(90 + 3)]. The precision of the method was ±2.2% (SD). The results with this method of assay of cholesterol 7α-hydroxylase were compared with those obtained with a method based on conversion of a trace amount of added [4-14C]cholesterol into 5-cholestene-3β,7α-diol.  相似文献   

6.
Neural tissues from adult, castrated male guinea pigs were examined for their capability to concentrate and metabolize [1,2-3H]testosterone (T) and [1,2-3H]dihydrotestosterone (DHT), both in vitro and in vivo. In vitro uptake of DHT and T was greater in the hypothalamus and anterior pituitary than in the cerebral cortex. With DHT as the substrate, the 800×g particulate concentration of this compound was highest in the hypothalamus, although in this tissue, particulate concentration was less than that of the cytoplasm. In the cerebral cortex 5α-androstane-3,17-dione was the most abundant metabolite, whereas 5α-androstane-3,17-dione, 5α-androstane-3α,17β-diol, and 5α-androstane-3β,17β-diol were all present in equivalent amounts in the hypothalamus and pituitary. Incubation with T resulted in the formation of DHT, 4-androstane-3,17-dione, and a compound with the mobility of 5α-(or 5β-)androstane-3,17-7-dione. The radioactivity associated with DHT was the most prevalent in the pituitary (1.3%), and least prevalent in the cerebral cortex (0.6%), and in all cases cytoplasmic concentration of this compound exceeded the concentration in the particulate fraction. Recrystallization failed to confirm the presence of estradiol-17β. Although there were no apparent tissue differences in the uptake of DHT or T 1 hour after their injection, intracellular distribution varied. In all tissues examined, that percentage of total radioactivity attributable to DHT was greatest in the 800×g particulate preparations, particularly in the hypothalamus. Thus neural tissues in the guinea pig, as in other species, exhibit differential uptake and metabolism of androgen through which physiological and behavioral effects may be mediated.  相似文献   

7.
The epididymis of adult rats metabolize 3H-testosterone by experiments in vivo. Thirty minutes after the injection of 100 μCi 3H-testosterone, some 10 per cent of the total radioactivity of the epididymis was found in the water-soluble fraction, whereas 90 per cent was found in the ether soluble fraction (free steroids). The free steroids were examined further and the following androgenic metabolites identified: testosterone (17β-hydroxy-4-androsten-3-one) 8, 9%, androstendipne (4-androstene-3, 17-dione, 2,7%,5α-A-dione (5α-androstane-3, 17-dione) 6,5%, DHT (17β-hydroxy-5α-androstan-3-one) 47, 2%, 3β-diol (5α-androstane-3β, 17β-diol) 4, 4%, 3α-diol (5α-androstane-3α,17β-diol) 20, 8% and androsterone (3α-hydroxy-5α-androstan-3-one) 3,4%. The relative amount of each metabolite is given in per cent of total radioactivity in the ether soluble fraction.  相似文献   

8.
A single thin layer chromatography and three antibodies were used for the specific radioimmunoassay of four androgens in pooled rat plasma (Sprague-Dawley adult males). The following values were found (pg/ml ± SD). Testosterone : 3, 138 ± 173; dihydrotestosterone : 374 ± 20; 5α-androstane-3α 17β-diol : 284 ± 24; 5α-androstane-3β, 17β-diol : 223 ± 11.  相似文献   

9.
The influence of androgens on the FSH modulation of progestin biosynthetic enzymes was studied 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.  相似文献   

10.
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 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.  相似文献   

11.
W W Peng  J R Wisner  D W Warren 《Steroids》1979,34(1):101-110
In the testes, 17β-hydroxy-5α-androstan-3-one (dihydrotestosterone, DHT) is converted to 5α-androstane-3α,17β-diol (3α-diol) by the enzyme 3α-hydroxysteroid oxidoreductase (3α-HSO). This steroid has been shown to possess biological activity in the male rat. The secretion of 3α-diol is much greater in the prepubertal animal than in the adult. This study is designed to quantitate the activity of 3α-HSO in the cytosol fraction of testes from male rats throughout sexual development. Following homogenizatlon of whole testes, the 105,000 × g supernatant or cytosol fraction was incubated with 3H DHT and varying concentrations of unlabelled DHT in the presence of 0.25μm NADPH. The incubation was carried out at 34°C for 10 min at a pH of 7.4. The Km of 3α-HSO in testicular cytosol was calculated to be 1.25μM. The specific activity of testicular cytosol 3α-HSO, expressed as pmoles of 3α-diol converted from DHT per min per mg testicular cytosol protein, was high in young rats from 10 to 22 days of age, and was followed by a decline between day 22 and 37, with activity remaining low throughout adulthood. Total testicular cytosol activity of 3α-HSO, expressed as nmoles of 3α-diol converted from DHT per min per pair of testes, gradually increased from day 10 to day 60 and remained high in the adult rat. In the post-pubertal period, a possible lack of available substrate, DHT, or possible endogenous testicular regulatory mechanisms acting on 3α-HSO activity might account for the actual decrease in 3α-diol concentration in the blood and testes of mature rats.  相似文献   

12.
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.  相似文献   

13.
O W Smith  P Ofner  R L Vena 《Steroids》1974,24(3):311-315
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.  相似文献   

14.
D K Lee  C E Bird  A F Clark 《Steroids》1973,22(5):677-685
The inhibitory effects of a variety of estrogens on rat prostate testosterone Δ4–5α-reductase activity were measured by a specific in vitro assay. The conversion of 3H-testosterone (initial concentration 2.8 × 10?9 M) to labelled 5α-dihydrotestosterone and 5α-androstane-3α, 17β-diol was used as a measure of Δ4?5a-reductase activity. At a concentration of 1.8 × 10?6 M, estradiol was the most potent inhibitor (83.4%) of the estrogens tested. Various ester derivatives, e.g. 3-acetate, 3-phosphate, were effective inhibitors. The 17-glucuronide and 3-sulfate conjugates were less effective inhibitors. The estriol isomers exerted similar degrees of inhibition (40–60%). The 3-methoxy derivatives of estradiol and estriol were poor inhibitors. The introduction of certain groups into the steroid structure, e.g. 15α-hydroxy and 6-ketone, greatly decreased the inhibitory effect of estradiol. The nature of the oxygen function at carbon 17 did not greatly influence the inhibitory effects.  相似文献   

15.
O. Djøseland 《Steroids》1976,27(5):617-636
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.  相似文献   

16.
James C. Coffey 《Steroids》1973,22(2):247-257
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.  相似文献   

17.
A major component of sexual maturation in the male rat is a progressive decline in serum concentrations of 5α-androstane-3α,17β-diol (3α-diol) and a concomitant increase in testicular testosterone biosynthesis and secretion. Chronic administration of synthetic luteinizing hormone releasing hormone (LHRH) or luteinizing hormone (LH)/human chorionic gonadotropin (hCG) to immature male rats has been shown to result in a delay in sexual maturation as evidenced by decreased sex accessory gland weights and altered testicular testosterone production. We have examined the postulate that such treatments may either reverse or retard the normal developmental pattern of serum testosterone and 3α-diol concentrations. Chronic in vivo treatment of 28 day old immature male rats for 2 weeks with daily injections of either 0.5 μg of LHRH, 1.0 μg of LHRH, or 30 μg of LH was found to result in significant reductions in weights of the seminal vesicles and ventral prostate glands and diminutions in serum testosterone concentrations. Serum content of 3α-diol was either unchanged or slightly elevated in the LHRH treated animals and increased significantly in the LH treated animals. These data suggest that either a reversal of or retardation in the normal developmental pattern of serum testosterone and 3α-diol content has been achieved in the immature male rat by chronic LHRH or LH treatment.  相似文献   

18.
M Matsui  Y Kinuyama  M Hakozaki 《Steroids》1974,24(4):557-573
A mixture of testosterone-4-14C and testosterone-1,2-3H-17-glucosiduronate was intraperitoneally administered into male and female rats with bile fistulas. Biliary metabolites were separated and purififd by a combination of column chromatography, enzymic hydrolysis or solvolysis of the conjugate fractions and identification of the liberated aglycones. The injected steroids were extensively metabolized and excreted predominantly in the blue. 5β-Androstane-3α, 17β-diol was found principally in monoglucosiduronate fraction and was produced preferentially from the injected conjugate in both sexes. Very marked sex differences from the injected conjugate in both sexes. Very marked sex differences were observed in the following metabolites: Androsterone was present only in the female as monoglucosidironate, which was preferentially derived from testosterone. 5α-Androstane-3α,17β-diol was identified in both monoglucosiduronate and diconjugate fractions of the female, which was formed significanrly more from the conjugate than testosterone. These findings provide evidence that testosterone glucosiduronate could be converted directly into 5α-steroids as well as 5β-ones invivo. In marked contrast, the major portion of testosterone was metabolized to polar steroids in the male.  相似文献   

19.
The in vivo and in vitro metabolism of (3H)-5α-androstane-α, 17β-diol by the male rat anterior pituitary was studied. A rapid and intensive conversion of 5α-androstane-3α,17β-diol into 5α-dihydrotestosterone was demonstrated, since following a 30 min. incubation time, 73 % of the recovered radioactivity were constituted by 5α-dihydrotestosterone. Studies on the subcellular distribution of steroids showed that 5α-dihydrotestosterone was the main steroid recovered except from the 105,000 × g pellet. From in vivo and in vitro experiments it was concluded that the transformation of 5α-dihydrotestosterone into 5α-androstane-3α,17β-diol was a reversible process, and that this last steroid could exert its biological action mainly via 5α-dihydrotestosterone.  相似文献   

20.
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 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.  相似文献   

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