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1.
Pubertal changes in the testicular steroid enzyme activities, responsible for the androgen production, were studied in rats in relation to the effects of testicular irradiation, followed by gonadotropin stimulation and cyproterone suppression. Five groups of pro-pubertal and adult rats were used in this study. The in vitro bioconversion from progesterone-4-14C and 17-hydroxyprogesterone-44C to testosterone, androstenedione, androstanediol, dihydrotestosterone and androsterone, demonstrated the effect of age in all cases of drug response investigations. The sexually immature animals in the control group had higher levels of androstenedione than testosterone, in contrast to the findings in the adults. With irradiation, androgen biosynthesis was suppressed in both age groups, which did not recover, under gonadotropin stimulation, in spite of the generation of new cells caused by the treatment. The irradiated adult testes demonstrated ‘pre-pubertal’ type bioconversion by catabolizing the substrates more towards 5α-reduced androgens, like androstanediol (5α-androstane-3α 17β-diol) and androsterone. With cyproterone the 17α-hydroxylase activities were found to be diminished.  相似文献   

2.
Cytoplasmic free and bound polysomes were isolated from bovine adrenal cortex, and used to program invitro protein synthesis in rat liver cell sap and wheat germ lysate systems. Synthesis of adrenodoxin(Ad) and adrenodoxin reductase(AdR) in the cell-free systems was determined by immunoprecipitation using monospecific antibodies, and the sizes of the invitro products were analyzed by SDS-polyacrylamide gel electrophoresis. Ad was synthesized by both free and bound polysomes as a putative large precursor having molecular weight of approximately 20,000 daltons, which was processed to mature size Ad (MW 12,000 daltons) by invitro incubation with adrenal cortex mitochondria. On the other hand, AdR was synthesized only by free polysomes apparently as the mature size product.  相似文献   

3.
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   

4.
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   

5.
Mouse L cell interferon (IFN αβ) inhibited the differentiation of mouse 3T3-Li fibroblasts into adipocytes. IFN αβ also inhibited hexose monophosphate shunt (HMP) activity in these cells. HMP activity is required for the reducing power necessary for the conversion of 3T3-Li fibroblasts to adipocytes. Both IFN blockage of differentiation and HMP activity were reversed by the reducing agent 2-mercaptoethanol, probably through interaction with membrane receptors and not through direct inactivation of IFN. Several non-antiviral effects of IFN αβ on cellular function, including differentiation and immunoregulation, may be mediated at the biochemical level through blockage of HMP activity.  相似文献   

6.
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   

7.
8.
Thirteen adult and one newborn heterozygotes, and three homozygotes for hemoglobin Constant Spring were examined for globin chain synthesis. Reticulocytes from venous blood were incorporated with [3H]-leucine in an incubation mixture for 3 hours. Globin prepared from the radioactive, washed red cells was fractionated by CM-cellulose chromatography in 8 M urea and the total radioactivity of each globin chain was determined. The mean of αβ ratio in the heterozygotes was 1.34 ± SD 0.08, which is significantly different from that of 1.07 ± SD 0.03 in eleven normal controls. The αβ+γ ratio in the heterozygous neonate was also 1.39. The αβ ratios in the three homozygotes were around 1.6. The α-Constant Spring chain appears to be over produced, but it may be unstable or labile, not fully available for conjugation with the non alpha chains.  相似文献   

9.
The anti-inflammatory analgesic drugs, aspirin, indomethacin, phenylbutazone, mefenamic acid, ibuprofen and flurbiprofen are shown to inhibit in a dose-dependent manner the force of contraction of isolated human pregnant myometrial strips which have been stimulated to contract by adding prostaglandin (PG) F to the tissue bath. These drugs and also flufenamic acid and salicin show a similar antagonism of the action of PGF with isolated rabbit non-pregnant myometrium. The ratio of the inhibitory concentration in vitro to the maximum plasma level after a normal dose in vivo suggests that phenylbutazone and possibly ibuprofen may be capable of inhibiting human uterine contractions in vivo. Patients who were treated with aspirin during induction of abortion using PGF during the second trimester of pregnancy showed no significant change in the induction-abortion interval compared with patients not taking aspirin.  相似文献   

10.
A series of 12α-hydroxy steroids with varying side chains was prepared, and their 24-hour acetylation yields were compared, l2α-Hydroxy-5β-pregnan-20-one (lb) was prepared from 3α, 12α-diacetoxy-5β~pregnan-20-one (2) and also by side chain degradation of 12α-acetoxy-5β-cholanoic acid (5d). 21-Benzyl-5β-pregnan-12α-ol (1g) was synthesized by hydrogenation of the 21-benzylidine derivative of ketone 1b. 23-Pheny1-5β-norcholan-12α-ol (1k) was obtained by the Grignard reaction of 2-phenyl-ethylmagnesium bromide and ketone 1b, dehydration, hydrogenation and hydride reduction; a similar sequence produced 20-methyl-5β-pregnan-12α-ol (lm). The acetylation results (Table 11) imply that branching at C-20 may be more significant for 12α-hydroxyl reactivity than side chain length or type. An additional compound with an unbranched side chain, 21-nor-5β-cholan-12α-ol (14), was synthesized by a Grignard reaction on the 21-bromo intermediate 11b. Acetylation rates determined by glc indicate (Table 111) That compounds with unbranched side chains have 12α-hydroxyl groups about ten times as reactive as their analogs with 20-methyl groups.  相似文献   

11.
A method was developed for quantitative determination of 5α,7α-dihydroxy-11-ketotetranor-prostane-1,16-dioic acid, the major urinary metabolite of prostaglandins F and F in man. The method was based on the use of the O-methyloxime derivative of [5β-3H; 10,10,12,12-2H4]5α,7α-dihydroxy-11-ketotetranor-prostane-1,16-dioic acid as internal standard and determination of ratios between unlabeled and deuterium-labeled molecules by multiple-ion analysis. Excretion values found for healthy human subjects were: males, 10.8–59.0 μg24 hr (n = 10, mean value, 24.0 ± 17.2 (SD) μg) and females, 7.6–13.6 μg24 hr (n = 10, mean value, 10.5 ± 2.1 (SD) μg).  相似文献   

12.
The in vitro and in vivo metabolism of 1,2- 3H-progesterone was studied in estrogen-stimulated and control vaginae of ovariectomized mice. Employing two-dimensional thin-layer chromatography, gas-liquid chromatography and metabolite “trapping” techniques, the major and minor pathways for progesterone metabolism were determined in vitro and shown to involve saturation of the Δ4-double bond to yield 5α-pregnane compounds and reduction of the C20 and C3 ketone groups to form 20α- and 3α- and 3β-hydroxy derivatives, respectively. The quantities of 20β-hydroxy metabolites and 5β-epimers that were detected were considered not to be significant. The major metabolites formed by untreated tissues following in vitro incubation in the presence of both high (10?6M) and low (10?8M) progesterone concentrations were 3α-hydroxy-5α-pregnan-20-one and 5α-pregnane-3,20-dione. Although these two derivatives were also found in sizable quantities in estrogen-treated tissues, a marked increase (5-fold) in the rate of C20 ketone reduction at high progesterone concentrations (10?6M) to yield 20α-hydroxy-4-pregnen-3-one was demonstrated. Following intravaginal administration of 3H-progesterone in vivo, only progesterone and 3α-hydroxy-5α-pregnan-20-one were retained in appreciable quantities through 2 hr, suggesting rapid loss of 20α-hydroxy-4-pregnen-3-one and the 5α-pregnanediols from this tissue under in vivo conditions.  相似文献   

13.
The constant infusion and single injection techniques were utilized to study the kinetics of 3H-testosterone (T) metabolism in postmenopausal women with and without breast cancer. The metabolic clearance rates (mean ± SEM) for normal postmenopausal women were 578 ± 82 and 644 ±128 124h as obtained by the constant infusion and single injection techniques, respectively. The corresponding results for the women with breast cancer (patients) are 644 ± 25 and 617 ± 106 124h. The single injection technique yielded values for rate constants (units) and volumes of distribution (1); k1 = 37.5 ± 1.6 for the normals and 34.5 ±1.9 for the patients. K2 = 76.6 ± 5.1 for the normals and 71.1 ± 1.6 for the patients, V1 = 7.9 ± 2.2 for the normals and 8.7 ± 1.4 for the patients and V2 = 7.0 ± 1.5 for the normals and 6.4 ± 1.2 for the patients. The constant infusion technique yielded values for the conversion ratios for the transformation of T to several products; 4-androstene-3,17-dione/T of 0.02 ± 0.003 for normals and 0.03± 0.002 for patients, 5α-dihydrotestosterone/T of 0.02 ± 0.002 for normals and 0.03 ± 0.002 for patients, estrone/T of 0.04 ± 0.01 for normals and 0.04 ± 0.01 for patients, estradiol-17β/T of 0.02 ± 0.005 for normals and 0.03 ± 0.005 for patients and estrone sulfate/T of O.16 ± 0.02 for normals and 0.24 ± 0.06 for patients. The T plasma concentrations and production rates were similar for the two groups of subjects. Hence there were no significant differences between the normals and the patients for all the kinetic parameters. It was determined that all the estradiol being produced in postmenopausal women could be coming from circulating T.  相似文献   

14.
A novel synthesis of 16α-hydroxy-4-androstene-3,17-dione (3), 16α-hydroxy-4-androstene-3, 6,17-trione (4), 17β-amino-5-androsten-3β-ol (10) and 17β-amino-4-androsten-3-one (14) is described. 16α-Bromoacetoxy-4-androstene-3, 17-dione (5), 16α-bromoacetoxy-4-androstene-3, 6,17-trione (6) and 17β-bromoacetylamino-4-androsten-3-one (15) were synthesized as potentially selective irreversible inhibitors of androgen aromatases. 16α-Bromo-4-androstene-3,17-dione (1) and 16α-bromo-4-androstene-3, 6,17-trione (2) were converted to compounds 3 and 4 in 80–90% yield by controlled stereospecific hydrolysis using sodium hydroxide in aqueous pyridine. Reductive amination of 3β-hydroxy-5-androsten-17-one and 3-methoxy-3,5-androstadien-17-one (11) using ammonium acetate and sodium cyanohydridoborate (NaBH3CN) and a subsequent treatment with acid gave the amines 10 and 14 respectively, as a salt. The corresponding 17-imino compounds 9 and 13 were also isolated from the reaction mixtures when methanol was used as a solvent for the reaction. The 16α-hydroxyl compounds 3 and 4 and the 17β-amino compound 14 were con- verted to the corresponding bromoacetyl derivatives, 5, 6, and 15, with bromoacetic acid and N,N'-dicyclohexylcarbodiimide.  相似文献   

15.
The effects of 19-hydroxy-prostaglandins (19-OH-PGs) were tested invivo on the rabbit oviduct and uterus and on the rhesus monkey (Macacamulatta) uterus. The 19-OH-PGEs suppressed spontaneous oviductal and uterine activity in the rabbit. The qualitative effect on the rabbit oviduct of 19-OH-PGEs was similar to that of PGE2. However, the typical response of the rabbit uterus to PGE2 was an increase in muscle activity. With regard to the rabbit oviduct, 19(R)-OH-PGE2 was as potent as PGE2, but 19(S)-OH-PGE2 was approximately 12 as potent as PGE2. Based on the dose of 19-OH-PGEs usually required to cause a minimal suppression and the dose of PGE2 required to cause a minimal stimulation of rabbit uterine activity, 19(R)-OH-PGE2 was twice as potent as PGE2 while 19(S)-OH-PGE2 was 12 as potent as PGE2. Stimulatory effects on the rabbit oviduct and uterus were observed following administration of 19-OH-PGEs and PGF. The potency on the rabbit oviduct of 19(S)-OH-PGF was about 15 to 110 that of PGF; the potency of 19(R)-OH-PGF was about 110 to 120 that of PGF. Both 19-OH-PGFs were approximately 15 to 110 as potent as PGF on the rabbit uterus. At the doses tested 19-OH-PGFs were inactive on the monkey uterus. Thus, these compounds are at least 15 as active as PGF. In contrast, 19(R)-OH-PGE2 had approximately the same potency as PGE2 in stimulating monkey uterine activity; but 19(S)-OH-PGE2 was approximately 13 as potent as PGE2.  相似文献   

16.
Resolution of (±)3-quinuclidinol into its enantiomers was obtained, at relatively high yield, based on the stereoselective enzymatic hydrolysis of R-(?)-3-quinuclidinyl butyrate by horse serum butyrylcholinesterase. The S-(+) isomer of 3-quinuclidinol was obtained from the racemate of 3-quinuclidinyl butyrate by a complete digestion of the (?) ester; the R-(?) isomer of 3-quinuclidinol was prepared by a partial hydrolysis of the racemate. The enantiomers obtained by this method were of high optical purity ([α]D25 = (+)46°). The cholinergic interactions of the benzilate esters of the 3-quinuclidinol enantiomers were characterized in mice in vivo and in isolated guinea pig ileum. The R to S potency ratio is around 10–15 for the muscarinic antagonist 3-quinuclidinyl benzilate (QNB) in the in vivo experiments compared to the reported ratio of 100 in competition experiments in vitro.  相似文献   

17.
The syntheses of (±) 2α,6β-diethyl-7α-ethynyl-3α-(p-hydroxyphenyl)-trans-bicyclo[4.3.0]nonan-7β-ol (8), (±)2β,6β-diethyl-7α-ethynyl-3β-(p-methoxyphenyl)-trans-bicyclo[4.3.0]nonan-7β-ol (12) and (±) 2α,6β-diethyl-7α-ethynyl-3β-(p-hydroxyphenyl)-trans-bicyclo[4.3.0]nonan-7β-ol (18) and their derivatives, which are essentially B-seco-steroids having cis-anti-trans, cis-syn-trans and trans-anti-trans geometries have been carried out. A study of their antiimplantation activities (AI) and receptor binding affinities (RBA) show that trans-anti-trans compounds are biologically most potent, followed by the corresponding cis-anti-trans and cis-syn-trans compounds. The most potent compound 18 is active at 1 mg/kg in rats. Introduction of 7α-ethynyl group increases their AI activity; however, no significant effect on their RBA is observed.  相似文献   

18.
Solid phase peptide synthesis of alpha-factor, a yeast mating pheromone.   总被引:5,自引:0,他引:5  
Based on analysis of highly purified preparations of natural α-factor and on the sequence recently reported by others, oligopeptides of the following structures were chemically synthesized by the solid phase method of Merrifield: N-Trp-His-Trp-Leu-Lys-Pro-Gly-G1N-Pro-Met-Tyr-C N-His-Trp-Leu-Lys-Pro-Gly-G1N-Pro-Met-Tyr-C Both synthetic species arrested a cells in G1, inhibited their DNA synthesis, caused them to elongate markedly, and induced an increase in their adhesivity toward α cells. Neither synthetic material caused any of these effects in α cells or in aα diploids.  相似文献   

19.
Q H Qazi  J G Hill 《Steroids》1973,22(3):311-325
A method is described for simultaneous determination of seven common urinary 17-ketosteroids, pregnanediol (5β-pregnane- 3α, 20α-diol) and pregnanetriol (5β-pregnane-3α,17α,20α-triol) by gas-liquid chromatography. The essential steps include hydrolysis of conjugates by an extract from Helixpomatia, use of 5β-cholestan-3α-ol as an internal standard, silylation and gas chromatography using 3% XE-60 as a stationary phase. The chromatograms were clear and the peaks easily identifiable. Laborious purification procedures were not necessary. 5β-pregnane-3α,20α-diol and 5β-pregnane-3α, 17α,20α-triol were measured in 22 adult males and 17 adult females. The subjects were trained hospital personnel, healthy and without medications. The results, in general, were in agreement with those reported by others.  相似文献   

20.
Y Ohno  J W Fisher 《Life sciences》1978,22(22):2031-2036
The mechanism of action of androgenic steroids on erythropoiesis is not well understood. In order to assess whether the site of action of androgens is on the early erythroid committed stem cell compartment, the invitro effects of testosterone (T), 5α-dihydrotestosterone (5α-DHT) and 5β-dihydrotestosterone (5β-DHT) on the so-called erythropoietic burst forming unit (BFU-E) in normal rabbit bone marrows were studied. Even though all of the steroids studied increased the number of BFU-E in the presece of Ep, 5β-DHT was the most potent in stimulating BFU-E. Testosterone was moderately effective in increasing BFU-E. Even though 5α-DHT produced a significant increase in BFU-E, it was the least effective of the 3 steroids studied. Preincubation (2 hrs) of normal rabbit bone marrow cells with testosterone followed by removal of T from the culture system resulted in a significant increase in BFU-E when compared with that of non-treated marrow cells in the presence of Ep. These data suggest that testosterone and 5β-DHT and possibly 5α-DHT act on an early uncommitted stem cell, perhaps the CFU-S, to increase the numbers of erythroid committed stem cells to eventually cause an increase in erythropoiesis in combination with Ep.  相似文献   

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