keyword
https://read.qxmd.com/read/7768324/glucuronosyltransferase-activity-in-human-cancer-cell-line-lncap
#21
JOURNAL ARTICLE
C Guillemette, A Bélanger
LNCaP, a human prostate cancer cell line, metabolizes testosterone into a variety of 5 alpha-reduced C19 steroids, such as dihydrotestosterone (DHT), androstane-3 alpha, 17 beta-diol (3 beta, 17 beta-DIOL), and androsterone (ADT). Recent reports also suggest that 5 alpha-reduced C19 steroid glucuronides can be detected in the medium. The purpose of this work was to characterize by liquid chromatograph ion spray mass spectroscopy (LCMS) the metabolites formed by LNCaP during incubation with testosterone and its 5 alpha-reduced C19 steroids...
February 1995: Molecular and Cellular Endocrinology
https://read.qxmd.com/read/7662274/steroidal-saponins-from-the-tubers-of-dichelostemma-multiflorum-and-their-inhibitory-activity-on-cyclic-amp-phosphodiesterase
#22
COMPARATIVE STUDY
T Inoue, Y Mimaki, Y Sashida, T Nikaido, T Ohmoto
Phytochemical examination of the tubers of Dichelostemma multiflorum led to the isolation of three new steroidal saponins together with two known saponins. The structures of the new compounds were determined by spectral data and a few chemical transformations to be (25R)-5 alpha-spirostane- 1 beta,3 beta-diol (brisbagenin) 1-O-[O-alpha-L-rhamnopyranosyl-(1-->3)-4-O- acetyl-alpha-L-arabinopyranoside], brisgabenin 1-O-[O-alpha-L-rhamnopyranosyl-(1-->2)-O- [alpha-L-rhamnopyranosyl-(1-->3)]-4-O-acetyl-alpha-L-arabinopyranosid e] and (22S,25S)-5 alpha-spirostan-3 beta-o1 3-O-[O-beta-D-galactopyranosyl- (1-->2)-O-[beta-D-xylopyranosyl-(1-->3)]-O-beta-D-glucopyranosyl-(1-->4) -beta-D-galactopyranoside]...
July 1995: Phytochemistry
https://read.qxmd.com/read/7641317/structures-of-steroidal-saponins-from-the-tubers-of-brodiaea-californica-and-their-inhibitory-activity-on-tumor-promoter-induced-phospholipid-metabolism
#23
JOURNAL ARTICLE
Y Mimaki, O Nakamura, Y Sashida, K Koike, T Nikaido, T Ohmoto, A Nishino, Y Satomi, H Nishino
Phytochemical examination of the fresh tubers of Brodiaea californica resulted in the isolation of four new steroidal saponins. Their structures were determined, by extensive spectral analysis including two-dimensional (2D) NMR spectroscopy and acid-catalyzed hydrolysis, to be (25S)-spirost-5-ene-1 beta,3 beta-diol [(25S)-ryscogenin] 1-O-[O-beta-D-glucopyranosyl-(1-->3)-O-alpha-L-rhamnopyranosyl-(1-->2)- beta-D-glucopyranoside] (1), (25S)-ruscogenin 1-O-[O-beta-D-glucopyranosyl-(1-->3)-O-alpha-L-rhamnopyranosyl-(1-->2)-O -[beta-D-xylopyranosyl-(1-->3)]-beta-D-glucopyranoside] (2), the C-20 and C-22 isomer of 2 (3) and the 6'-O-acetyl derivative of 2 (4), respectively...
June 1995: Chemical & Pharmaceutical Bulletin
https://read.qxmd.com/read/7542902/potential-activities-of-androgen-metabolizing-enzymes-in-human-prostate
#24
JOURNAL ARTICLE
M Krieg, H Weisser, S Tunn
The entire androgen metabolism of the human prostate is an integral part of the DHT mediated cellular processes, which eventually give rise to the androgen responsiveness of the prostate. Therefore, the potential activities of various androgen metabolizing enzymes were studied. Moreover, the impact of aging on the androgen metabolism and the inhibition of 5 alpha-reductase by finasteride were studied. In epithelium (E) and stroma (S) of normal (NPR) and hyperplastic human prostate (BPH), for each enzyme being involved in the conversion either of testosterone via DHT, 3 alpha- and 3 beta-diol to the C19O3-triols or from testosterone to androstenedione and vice versa, the amount (Vmax) and Michaelis constant (Km) were determined by Lineweaver-Burk plots...
June 1995: Journal of Steroid Biochemistry and Molecular Biology
https://read.qxmd.com/read/7419267/peripheral-serum-corticosteroid-concentrations-in-relation-to-the-rat-adrenal-cortical-circadian-rhythm-in-androgen-induced-hypertension
#25
JOURNAL ARTICLE
C S Fink, S Gallant, A C Brownie
Adrenal function was assessed in control rats and in rats treated for 2 and 4 weeks with 17 alpha-methylandrostenediol (MAD; 17 alpha-methyl-5-androstene-3 beta-diol), a synthetic androgen known to produce hypertensive cardiovascular disease. In both groups and at both time periods, a circadian rhythm of blood corticosteroid concentrations was observed. The high point for serum corticosterone (B), 18-hydroxy-11-deoxycorticosterone (18-hydroxy-DOC), and 11-deoxycorticosterone (DOC) concentrations occurred at the beginning of the dark period (1800 hours), and the low point occurred at the onset of the light period (0600 hours)...
September 1980: Hypertension
https://read.qxmd.com/read/7404603/simultaneous-measurements-of-testosterone-and-three-5-alpha-reduced-androgens-in-the-venous-effluent-of-immature-rat-testes-in-situ
#26
COMPARATIVE STUDY
R G Foldesy, J H Leathem
Simultaneous measurements were made by radioimmunoassay of testosterone, 17 beta-hydroxy-5 alpha-androstan-3-one (DHT), 5 alpha-androstane-3 alpha, 17 beta-diol (3 alpha-diol), and 5 alpha-androstane-3 beta, 17 beta-diol (3 beta-diol) in the testicular venous plasma (TVP) and peripheral plasma (PP) of 30, 45, and 55 day old rats. At 30 days of age, the preponderant androgen in both plasmas was 3 alpha-diol but testosterone predominated by day 55. Testosterone levels increased with age in both TVP (6.39, 15...
June 1980: Steroids
https://read.qxmd.com/read/7394856/ruizgenin-a-new-steroidal-sapogenin-diol-from-agave-lecheguilla
#27
JOURNAL ARTICLE
G Blunden, A Carabot, A L Cripps, K Jewers
From the leaves of Agave lecheguilla Torrey, two steroidal sapogenin diols have been isolated. Mass spectral, infra-red and nuclear magnetic resonance data of these two compounds showed them to be (25R)-spirost-5-ene-2 alpha, 3 beta-diol (yuccagenin) and (25R)-5 beta-spirostane-3 beta, 6 alpha-diol. The latter is a new compound to which the trivial name ruizgenin has been given.
May 1980: Steroids
https://read.qxmd.com/read/7378912/studies-on-the-interaction-of-5-alpha-androstane-3-beta-17-beta-diol-with-the-testicular-estrogen-receptor
#28
COMPARATIVE STUDY
W H Moger
5 alpha-Androstane-3 beta,17 beta-diol (3 beta-diol) was observed to inhibit [3H]estradiol ([3H]E2) binding to testicular cytosol preparations from both immature and mature rats with a potency of 1% that of diethylstilbestrol. The nature of the inhibition of [3H]E2 binding by 3 beta-diol was shown to be competitive with a KI of approximately 12 nM. This high competitive potency for a C19 steroid required both 3 beta- and 17-hydroxyl groups,, and reduced C5 position to inhibit E2 binding. Despite the interaction of 3 beta-diol with E2 receptor in vitro, injection of immature rats with 25 or 250 microgram 3 beta-diol 1-6 h before autopsy did not occupy or deplete the testicular cytoplasmic E2 receptor...
February 1980: Canadian Journal of Physiology and Pharmacology
https://read.qxmd.com/read/7376215/the-identification-and-characterization-of-the-c19o3-steroid-metabolites-of-5-alpha-androstane-3-beta-17-beta-diol-produced-by-the-canine-prostate-5-alpha-androstane-3-beta-6-alpha-17-beta-triol-and-5-alpha-androstane-3-beta-7-alpha-17-beta-triol
#29
JOURNAL ARTICLE
J T Isaacs, I R McDermott, D S Coffey
This study has identified the polar metabolites of 5 alpha-androstane-3 beta-17 beta-diol(3 beta-diol) produced by the canine prostate. The major metabolite is 5 alpha-androstane-3 beta,7 alpha,17 beta-triol(7 alpha-triol) accounting for approximately 80% of the total polar metabolites of 3 beta-diol. The remaining 20% is accounted for exclusively by another triol, 5 alpha-androstane-3 beta,6 alpha,17 beta-triol(6 alpha-triol). This study has also characterized two enzymatic hydroxylase responsible for respective triol formation: 5 alpha-androstane-3 beta,17 beta-diol 6 alpha-hydroxylase(6 alpha-hydroxylase) and 5 alpha-androstane-3 beta,17 beta-diol 7 alpha-hydroxylase(7 alpha-hydroxylase)...
February 1980: Steroids
https://read.qxmd.com/read/7241236/effect-of-wavelength-on-the-formation-of-1-alpha-hydroxyprevitamin-d3-in-the-ultraviolet-irradiation-of-cholesta-5-7-diene-1-alpha-3-beta-diol-and-use-of-a-filter-solution-in-the-photochemical-reaction-in-the-synthesis-of-1-alpha-hydroxyvitamin-d3
#30
JOURNAL ARTICLE
T Sato, H Yamauchi, Y Ogata, T Kunii, K Kagel, G Katsui, S Toyoshima, M Yasumura, T Kobayashi
No abstract text is available yet for this article.
1980: Journal of Nutritional Science and Vitaminology
https://read.qxmd.com/read/7214161/metabolic-control-of-the-behavioural-action-of-androgens-in-the-dove-brain-testosterone-inactivation-by-5-beta-reduction
#31
JOURNAL ARTICLE
T Steimer, J B Hutchison
In vitro studies of androgen metabolism in the dove brain show that testosterone is rapidly converted to 5 beta-reduced metabolites (5 beta-dihydrotestosterone and the two corresponding 3 alpha/3 beta diols). The preoptic region and the anterior ventromedial and posterior hypothalamus which are target areas for androgen action on behaviour and the neuroendocrine system show significantly less 5 beta-reduction than adjacent parolfactory, septal and striatal areas not directly involved in androgen action. In contrast to 5 alpha-reduction and aromatization, which lead to the formation of active metabolites in the dove brain, 5 beta-reduction is likely to be part of a testosterone (T) inactivation mechanism because: (a) intrahypothalamic implants of 5 beta-dihydrotestosterone were ineffective for male behaviour in the dove; (b) 5 beta-reduced metabolites of T were not detected in hypothalamic cell nuclei following intramuscular injection of tritiated testosterone, and were rapidly eliminated from brain cells; (c) the 4 beta-diols were also found to be a major product of T catabolism in the liver, a site of androgen inactivation...
March 23, 1981: Brain Research
https://read.qxmd.com/read/7165125/effect-of-5-alpha-reduced-androgens-on-prolactin-secretion
#32
JOURNAL ARTICLE
F Celotti, N Avogadri, P Negri-Cesi, M Motta
The effects of a 6-day treatment with 2 mg/day of testosterone, dihydrotestosterone (DHT), 5 alpha-androstan-3 alpha, 17 beta-diol (3 alpha-diol) and 5 alpha-androstan-3 beta, 17 beta-diol (3 beta-diol) on serum prolactin levels have been evaluated in long-term castrated male and female rats. The steroids were administered either in the free alcohol or in the propionated form (mono and dipropionates for the 3 alpha- and 3 beta-diols). Practically no effect of any steroid was evident in the treated male animals...
November 1982: Andrologia
https://read.qxmd.com/read/7082691/-specific-binding-of-3h-5-alpha-androstane-3-beta-17-beta-diol-by-cytosol-from-male-and-female-rat-hypophysis
#33
JOURNAL ARTICLE
V G Degtiar'
Evidence for specific binding of [3H]5 alpha-androstane-3 beta, 17 beta-diol (3 beta-diol) in the cytosol of male and female rats was confirmed by determining the apparent dissociation constant and the number of binding sites calculated by the Scatchard method. Centrifugation of hypophysial cytosols in sucrose density gradient revealed the binding at 4.5 S and 8--8.5 S and specific binding of 3 beta-diol around 4.5 S. The presence of protein-bound radioactivity was shown by gel-filtration of Sephadex G-200...
April 1982: Biokhimii︠a︡
https://read.qxmd.com/read/6887908/on-the-significance-of-5-alpha-androstane-3-alpha-17-beta-diol-in-the-peripubertal-female-rat
#34
JOURNAL ARTICLE
K B Ruf
The biological effects of exogenous 5 alpha-androstane-3 alpha,17 beta-diol (3 alpha-diol) and its 3 beta-epimer (3 beta-diol) on sexual maturation were assessed in Sprague-Dawley rats. Chronic administration of 3 alpha-diol, but not of 3 beta-diol, prevented ovulation and suppressed uterine and ovarian development. Vaginal opening was advanced by 3 alpha-diol, but neither vaginal cytology nor ovarian histology revealed any signs of ovarian cyclicity. When administered acutely, 3 alpha-diol prevented the estrogen-priming required for the triggering of gonadotropin surges by progesterone as well as the estrogen-sensitization of pituitary gonadotrophs to LHRH stimulation...
July 1983: Journal of Steroid Biochemistry
https://read.qxmd.com/read/6887907/blood-concentrations-and-biological-effects-of-androstanediols-at-the-onset-of-puberty-in-the-female-rat
#35
JOURNAL ARTICLE
B Eckstein
Androstanediols are the major products of the immature rat ovary. About two-thirds are present in blood as sulfates. One of the sulfate conjugates was identified as 5 alpha-androstane-3 beta,17 beta-diol-3-monosulfate. This steroid effectively inhibits postcastrational LH elevation in a concentration in which it is present in blood. Other androstanediol sulfates examined were without this activity. In the immature rat, levels of 3 alpha- and 3 beta-diol decrease sharply before the first ovulation. In Wistar rats, PMSG-treatment induced a similar decline in these steroids...
July 1983: Journal of Steroid Biochemistry
https://read.qxmd.com/read/6859560/unconjugated-5-alpha-androstan-3-alpha-17-beta-diol-and-5-alpha-androstane-3-beta-17-beta-diol-in-normal-and-pathological-human-seminal-plasma-comparison-with-testosterone-5-alpha-dihydrotestosterone-and-testosterone-glucosiduronate
#36
COMPARATIVE STUDY
E Kurniawan, J Tamm, U Volkwein, C Schirren
By means of specific RIA unconjugated 5 alpha-androstan-3 alpha, 17 beta-diol (3 alpha-diol) and 5 alpha-androstane-3 beta, 17 beta-diol (3 beta-diol) have been estimated for the first time in normal and pathological human seminal plasma. Testosterone, 5 alpha-dihydrotestosterone and testosterone-glucosiduronate (T, DHT, TG) have been determined simultaneously. On average a significant decrease of both diols was established in seminal plasma obtained from males suffering from oligozoospermia, azoospermia, asthenozoospermia and teratozoospermia...
March 1983: Andrologia
https://read.qxmd.com/read/6822214/decrease-in-blood-and-ovarian-3-alpha-and-3-beta-androstanediol-levels-in-rats-induced-to-ovulate-with-pregnant-mare-serum-gonadotropin
#37
JOURNAL ARTICLE
B Eckstein, A Nimrod, F Kohen
Several hours before the first ovulation progesterone metabolism in the rat ovary, in vitro, is shifted from the production of 5 alpha-androstane-3 alpha, 17 beta-diol (3 alpha-diol) as the major metabolite toward the production of 4-ene-3-oxosteroids. In the present paper, changes in levels of 3 alpha-diol and its 3 beta-epimer as well as testosterone in blood and ovaries around the time of the first ovulation have been studied in immature PMSG-treated rats. Forty-eight hours after PMSG, a considerable increase in blood and ovarian testosterone concentration was observed, whereas the concentrations of both androstanediols in blood decreased sharply...
March 1983: Endocrinology
https://read.qxmd.com/read/6796306/control-of-gonadotrophin-secretion-by-steroid-hormones-in-castrated-male-transsexuals-ii-effects-of-androgens-alone-and-in-combination-with-oestradiol-on-the-secretions-of-fsh-and-lh
#38
JOURNAL ARTICLE
H H Goh, S M Karim, S S Ratnam
Twenty-nine infusions in twenty castrated male transsexual volunteers were carried out over a period of 7 h with subjects lying in the supine position. The effects of different doses of testosterone and its 5 alpha-reduced metabolites as well as the effect of testosterone in combination with oestradiol on gonadotrophin secretion were evaluated. Different and varying degrees of suppression of plasma levels of FSH and LH were observed. The infusions of 2.4 mg testosterone, 5 alpha-androstan-3 alpha-17 beta-diol (3 alpha-diol), 5 alpha-androstan-3 beta-17 beta-diol (3 beta-diol) but not dihydrotestosterone (DHT) caused significant suppression of LH...
September 1981: Clinical Endocrinology
https://read.qxmd.com/read/6696957/plasma-concentrations-of-free-5-alpha-androstane-3-alpha-17-beta-diol-and-related-gonadal-steroids-during-spontaneous-and-induced-sexual-maturation-in-the-female-rat
#39
JOURNAL ARTICLE
J Cohen, C Doré, B Robaire, K B Ruf
Plasma concentrations of free 5 alpha-androstane-3 alpha, 17 beta-diol (3 alpha-diol), 5 alpha-androstane-3 beta, 17 beta-diol (3 beta-diol), 5 alpha-dihydrotestosterone (DHT) and of testosterone (T) were determined in female rats undergoing spontaneous sexual maturation or pregnant mare's serum gonadotropin (PMSG)-induced precocious ovulation. In the prepubertal period, 3 alpha-diol levels showed an inverse relationship with uterine weights and a significant drop between Days 21 and 26 of life. Postpubertally, 3 alpha-diol concentrations tended to rise again, to a lesser degree, in parallel with increments in plasma T...
February 1984: Biology of Reproduction
https://read.qxmd.com/read/6638538/in-vitro-metabolism-of-3h-androstenedione-in-the-rat-epididymis-and-vas-deferens
#40
JOURNAL ARTICLE
B S Setty, J T Leask, G M Waites
The in vitro metabolism of (3H)-androstenedione in the epididymis and vas deferens of intact and castrated rats was investigated and the metabolites formed were identified by radio gas chromatography. Incubation of slices of caput epididymidis for 2 hr at 34 degrees C metabolised 90% androstenedione. Similar incubations of tissue samples from cauda epididymidis and vas deferens metabolized 60 and 25% of androstenedione respectively. The major metabolites formed in the epididymis were androstanedione (caput: 48%; cauda: 33%) and androsterone (caput: 35%; cauda: 13%)...
July 1983: Andrologia
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