keyword
https://read.qxmd.com/read/9745441/plasma-adrenal-gonadal-and-conjugated-steroids-before-and-after-long-term-overfeeding-in-identical-twins
#21
JOURNAL ARTICLE
J Pritchard, J P Després, J Gagnon, A Tchernof, A Nadeau, A Tremblay, C Bouchard
An analysis of the data collected in the Quebec Overfeeding Study of identical twins was undertaken to determine any evidence of a genotype effect on plasma levels of adrenal and gonadal steroids arising from long term positive energy balance. Plasma levels of sex hormone-binding globulin (SHBG), testosterone, dihydrotestosterone (DHT), dehydroepiandrosterone sulfate (DHEA-S), androsterone glucuronide, androstane-3 alpha, 17 beta-diol glucuronide (3 alpha-DIOL-G), and cortisol were measured in 12 pairs of young, sedentary, male monozygotic twins before and after 100 days of overfeeding...
September 1998: Journal of Clinical Endocrinology and Metabolism
https://read.qxmd.com/read/9695138/androgenic-neurosteroids-anti-seizure-effects-in-an-animal-model-of-epilepsy
#22
JOURNAL ARTICLE
C A Frye, T A Reed
These studies investigate whether the neurosteroid and 5 alpha-reduced metabolite of testosterone (T), 5 alpha-androstane-3 alpha, 17 beta-diol (3 alpha-Diol), has anti-seizure effects similar to its parent compound. In experiment 1, ovariectomized (ovx) Long-Evans rats (n = 20) were subcutaneously (s.c.) administered 32 mg/kg kainic acid or saline vehicle 10 min following 0.0, 3.0, or 7.5 mg/kg 3 alpha-Diol in 10% ethanol, propylene glycol vehicle (veh). During 2 h of observation of ictal activity, 3 alpha-Diol (3...
May 1998: Psychoneuroendocrinology
https://read.qxmd.com/read/9666347/crosstalk-between-normal-and-tumoral-brain-cells-effect-on-sex-steroid-metabolism
#23
JOURNAL ARTICLE
R C Melcangi, I Cavarretta, V Magnaghi, M Ballabio, L Martini, M Motta
The present article shows for the first time that two cell lines derived respectively from a rat glioma (C6 cell line) and from a human astrocytoma (1321N1 cell line) are able to convert testosterone and progesterone into their corresponding 5 alpha-reduced metabolites dihydrotestosterone and dihydroprogesterone. Moreover, both cell lines are also able to convert these metabolites further into their corresponding 3 alpha-OH derivatives, 5 alpha-androstan-3 alpha, 7 beta-diol (3 alpha-diol) and tetrahydroprogesterone...
February 1998: Endocrine
https://read.qxmd.com/read/9618803/insulin-like-growth-factor-i-and-ii-in-human-benign-prostatic-hyperplasia-relationship-with-binding-proteins-2-and-3-and-androgens
#24
JOURNAL ARTICLE
S Monti, F Di Silverio, S Lanzara, P Varasano, C Martini, C Tosti-Croce, F Sciarra
In prostatic tissue, androgen action may be mediated by growth factors such as insulin-like growth factor-I (IGF-I) and II (IGF-II), which are mitogenic for prostatic cells and modulate the stroma-epithelium interaction. IGF-binding proteins (IGFBPs) have an autocrine and/or paracrine role in regulating the local actions of the IGFs. In this study, testosterone, dihydrotestosterone (DHT), 3 alpha androstanediol (3 alpha diol), IGF-I, IGF-II, IGFBP2, and IGFBP3 concentrations were evaluated in human benign prostatic hyperplasia (BPH) tissue...
May 1998: Steroids
https://read.qxmd.com/read/9521675/mutagenesis-of-3-alpha-hydroxysteroid-dehydrogenase-reveals-a-push-pull-mechanism-for-proton-transfer-in-aldo-keto-reductases
#25
COMPARATIVE STUDY
B P Schlegel, J M Jez, T M Penning
Rat liver 3 alpha-hydroxysteroid dehydrogenase (3 alpha-HSD, E.C. 1.1.1.213, AKR1C9) is a member of the aldo-keto reductase (AKR) superfamily which inactivates circulating steroid hormones. We have proposed a catalytic mechanism in which Tyr 55 acts as a general acid with its pK value being lowered by a hydrogen bond with Lys 84 which is salt-linked to Asp 50. To test this mechanism, residues at the active site were mutated and the mutant enzymes (Y55F, Y55S, K84M, K84R, D50N, D50E, and H117A) were purified to homogeneity from an Escherichia coli expression system...
March 10, 1998: Biochemistry
https://read.qxmd.com/read/9491251/the-effect-of-microgravity-on-testicular-androgen-secretion
#26
JOURNAL ARTICLE
F Strollo, G Riondino, B Harris, G Strollo, E Casarosa, N Mangrossa, C Ferretti, M Luisi
BACKGROUND: Spaceflight causes a number of physiological changes in the human body. Most would consider space travel to be a stressful event even for well-trained astronauts. Should this be true, pituitary gonadotrophins (mainly LH) and testicular androgens, like testosterone (T), should decrease inflight in male astronauts. We therefore hypothesized that lowered testicular androgen levels might occur in men during spaceflight, due to stress-dependent lowered LH concentrations. METHODS: In order to test this hypothesis, on different day pre-, in- and postflight we assayed wake-time salivary and urinary T in four astronauts, as well as wake-time plasma levels of adrenocorticotropin (ACTH), cortisol (CS), LH, T and its peripherally active metabolite 3-alpha-diol glucuronide (3ADG)...
February 1998: Aviation, Space, and Environmental Medicine
https://read.qxmd.com/read/9439933/serum-androgen-levels-in-hyperthyroid-women
#27
JOURNAL ARTICLE
H Ueshiba, S Takeda, H Matoba, Y Tanaka, R Yuasa, K Tsuboi, Y Miyachi
Thyroid hormone is known to affect androgen metabolism, however, there are few studies in which alterations of androgen metabolism are simultaneously examined in patients with clinical thyroid disorders. In this study, we investigated the alterations of thyroid hormone and androgens before and during treatment in patients with hyperthyroidism. Fifteen female patients with hyperthyroidism due to Graves' disease were studied. From these patients, blood samples were obtained before treatment and at 1 month (M), 2M, 3M, 4M and 6M after beginning of treatment...
1997: Experimental and Clinical Endocrinology & Diabetes
https://read.qxmd.com/read/9253307/marked-decline-in-serum-concentrations-of-adrenal-c19-sex-steroid-precursors-and-conjugated-androgen-metabolites-during-aging
#28
JOURNAL ARTICLE
F Labrie, A Bélanger, L Cusan, J L Gomez, B Candas
The present data show a dramatic decline in the circulating levels of dehydroepiandrosterone (DHEA), DHEA-sulfate (DHEA-S), androst-5-ene-3 beta,17 beta-diol (5-diol), 5-diol-sulfate, 5-diol-fatty acid esters, and androstenedione in both men and women between the ages of 20-80 yr. In the 50- to 60-yr-old group, serum DHEA decreased by 74% and 70% from its peak values in 20- to 30-yr-old men and women, respectively. the serum concentrations of the conjugated metabolites of dihydrotestosterone (DHT), namely androsterone (ADT)-G, androstane-3 alpha,17 beta-diol (3 alpha-diol-G), androstane-3 beta,17 beta-diol (3 beta-diol-G), and ADT-sulfate are the most reliable parameters of the total androgen pool in both men and women, whereas serum testosterone and DHT can be used as markers of testicular secretion in men and interstitial ovarian secretion in women...
August 1997: Journal of Clinical Endocrinology and Metabolism
https://read.qxmd.com/read/9154505/androgen-udp-glucuronyl-transferase-activity-is-found-primarily-in-the-liver-in-the-human
#29
JOURNAL ARTICLE
E C Pirog, D C Collins
In this study, androgen UDP-glucuronyl transferase (UDPGT) activity was determined in microsomes of human liver, skin, and prostate. Androgen UDPGT activity was highest in the liver microsomes using 5 alpha-androstane-3 alpha, 17 beta-diol (3 alpha DIOL), androsterone (AN) and dihydrotestosterone (DHT) as substrates. The Km and Vmax values and enzyme velocity at the physiological concentration of the substrates in the liver microsomes were similar for AN and 3 alpha DIOL. The values for AN were as follows: Km = 16...
March 1997: Journal of Andrology
https://read.qxmd.com/read/8993793/5-alpha-reductase-activity-and-prostate-cancer-a-case-control-study-using-stored-sera
#30
JOURNAL ARTICLE
H A Guess, G D Friedman, M C Sadler, F Z Stanczyk, J H Vogelman, J Imperato-McGinley, R A Lobo, N Orentreich
We report a nested case-control study of serum biomarkers of 5 alpha-reductase activity and the incidence of prostate cancer. From a cohort of more than 125,000 members of the Kaiser Permanente Medical Care Program who underwent multiphasic health examinations during 1964-1971, we selected 106 incident prostate cancer cases. A control was pair matched to each case on age, date of serum sampling, and clinic location. Serum levels of total testosterone, free testosterone, androsterone glucuronide, and 5 alpha-androstane-3 alpha,17 beta androstanediol glucuronide (3 alpha-diol G) were measured on the stored samples and scored as quartiles...
January 1997: Cancer Epidemiology, Biomarkers & Prevention
https://read.qxmd.com/read/8889005/progesterone-and-3-alpha-androstanediol-conjugated-to-bovine-serum-albumin-affects-estrous-behavior-when-applied-to-the-mbh-and-poa
#31
JOURNAL ARTICLE
C A Frye, K R Van Keuren, P N Rao, M S Erskine
Ovariectomized rats with cannula over the medial basal hypothalamus (MBH) received implants of 3 alpha-diol conjugated to bovine serum albumin (BSA; 3 alpha-diol:BSA), free 3 alpha-diol diluted with BSA (3 alpha-diol&BSA), progesterone (P) conjugated to BSA (P:BSA), free P diluted with BSA (P&BSA), or BSA alone. 3 alpha-diol:BSA or 3 alpha-diol&BSA facilitated receptivity within 90 min. Other estradiol-treated rats received steroid implants in the preoptic area (POA); those receiving P:BSA or P&BSA showed significant elevations in lordosis in 5 min...
June 1996: Behavioral Neuroscience
https://read.qxmd.com/read/8883823/behavioral-effects-of-3-alpha-androstanediol-ii-hypothalamic-and-preoptic-area-actions-via-a-gabaergic-mechanism
#32
JOURNAL ARTICLE
C A Frye, J E Duncan, M Basham, M S Erskine
We investigated whether 5 alpha-androstane-3 alpha, 17 beta-diol (3 alpha-androstanediol; 3 alpha-Diol), a neurosteroid whose effects are primarily inhibitory to sexual behavior, may act through interactions with gamma-aminobutyric acid (GABA) receptor complexes (GBRs) in the medial basal hypothalamus (MBH) and the preoptic area (POA). In Experiment (Exp.) 1, ovariectomized (ovx) rats were implanted with bilateral guide cannulae aimed above the MBH and were later treated with 17 beta-estradiol (E2, 2 injections of 1 microgram/0...
September 1996: Behavioural Brain Research
https://read.qxmd.com/read/8883822/behavioral-effects-of-3-alpha-androstanediol-i-modulation-of-sexual-receptivity-and-promotion-of-gaba-stimulated-chloride-flux
#33
JOURNAL ARTICLE
C A Frye, K R Van Keuren, M S Erskine
Pregnane neurosteroids may initiate sexual receptivity not only via actions at intracellular receptors, but by affecting gamma-aminobutyric acid (GABA) receptor complexes (GBRs). To investigate whether GBR-mediated actions of an androgenic neurosteroid 5 alpha-androstane-3 alpha, 17 beta-diol (3 alpha-androstanediol; 3 alpha-Diol) may influence the expression of sexual behavior, ovariectomized (ovx) rats received daily injections of 3 alpha-Diol (0.6, 3.0, 6.0 and 7.5 mg/kg) or vehicle (10% (v/v) ethanol in propylene glycol) at 10...
September 1996: Behavioural Brain Research
https://read.qxmd.com/read/8869550/analgesic-effects-of-the-neurosteroid-3-alpha-androstanediol
#34
JOURNAL ARTICLE
C A Frye, K R Van Keuren, P N Rao, M S Erskine
The efficacy of 5 alpha-androstane-3 alpha,17 beta-diol (3 alpha-Androstanediol; 3 alpha-Diol) and 4-pregnen-3,20-dione (progesterone; P) in promoting analgesia was investigated. Ovariectomized rats received daily injections of 3 alpha-Diol (0.6, 3.0, 6.0 and 7.5 mg/kg) or vehicle and twice daily injections of estradiol-17 beta (E2: 1 microgram) for 2 days. Progesterone (0.5, 1.0, 2.0 and 4.0 mg/kg) or its vehicle was given on the third day and nociceptive testing using the radiant heat tailflick method was carried out 4 h later...
February 12, 1996: Brain Research
https://read.qxmd.com/read/8844881/effects-of-paced-and-non-paced-mating-stimulation-on-plasma-progesterone-3-alpha-diol-and-corticosterone
#35
JOURNAL ARTICLE
C A Frye, C M McCormick, C Coopersmith, M S Erskine
In the female rat, gonadal and adrenal progestins and androgens modulate sexual receptivity and in turn, their levels increase in response to mating stimulation. Paced mating, in which the female controls the timing of sexual contacts with the male, is particularly effective at eliciting acute increases in progesterone (P) and 5 alpha-Androstane-3 alpha, 17 beta-diol (3 alpha-Diol). Interestingly, restraint stress produces comparable increases in P and 3 alpha-Diol levels, as well as increases in corticosterone (CORT) levels...
May 1996: Psychoneuroendocrinology
https://read.qxmd.com/read/8833738/the-mrnas-for-the-steroid-5-alpha-reductase-isozymes-types-1-and-2-are-differentially-regulated-in-the-rat-epididymis
#36
JOURNAL ARTICLE
R S Viger, B Robaire
The enzyme steroid 5 alpha-reductase (EC 1.3.1.22) catalyzes the conversion of testosterone to its more potent form, dihydrotestosterone (DHT), in many androgen-sensitive target tissues. In the epididymis, the 5 alpha-reduced metabolites of testosterone, DHT and 5 alpha-androstan-3 alpha, 17 beta-diol (3 alpha-diol), are considered the primary regulators of epididymal structure and function. Two rat 5 alpha-reductase transcripts, designated types 1 and 2, have been identified. Our laboratory has previously characterized the endocrine and developmental regulation of the 5 alpha-reductase type 1 mRNA in the rat epididymis...
January 1996: Journal of Andrology
https://read.qxmd.com/read/8818396/testosterone-and-progesterone-metabolism-in-the-central-nervous-system-cellular-localization-and-mechanism-of-control-of-the-enzymes-involved
#37
REVIEW
L Martini, F Celotti, R C Melcangi
This paper summarizes the most recent data obtained in the authors' laboratory on the metabolism of testosterone and progesterone in neurons and in the glia. 1. The activities of 5 alpha-reductase (the enzyme that converts testosterone into dihydrotestosterone; DHT) and of 3 alpha-hydroxy steroid dehydrogenase (the enzyme that converts DHT into 5 alpha-androstane-3 alpha, 17 beta-diol; 3 alpha-diol) were first evaluated in primary cultures of neurons, oligodendrocytes, and type-1 and type-2 astrocytes, obtained from the fetal or neonatal rat brain...
June 1996: Cellular and Molecular Neurobiology
https://read.qxmd.com/read/8789735/steroid-growth-factor-interaction-in-human-prostate-cancer-2-effects-of-transforming-growth-factors-on-androgen-metabolism-of-prostate-cancer-cells
#38
JOURNAL ARTICLE
G Carruba, O M Granata, R Farruggio, S Cannella, A L Bue, R E Leake, M Pavone-Macaluso, L A Castagnetta
The ability of human prostate cancer cells to metabolize androgens was assessed through administration of physiological concentration (0.5-10 nM) of tritiated testosterone (T) as precursor and one-step analysis of both T degradation and products' formation by reverse-phase HPLC and on-line radioactive detection after either 24 h or 72 h incubation. Overall, different prostate cancer cells degraded T quite differently, favoring alternatively reductive or oxidative metabolic pathways. In particular, both LNCaP and DU145 cells retained high levels of unconverted T, with a limited production of androstenedione and its 17-keto derivatives and relatively high amounts of dihydrotestosterone (DHT) and 3 alpha-androstanediol (3 alpha-diol)...
January 1996: Steroids
https://read.qxmd.com/read/8759411/-tests-of-adrenal-gland-and-ovarian-function-in-the-hyperandrogenemia-syndrome
#39
JOURNAL ARTICLE
Z Giljević
Androgen production in women is under the influence of pituitary hormones on ovaries and adrenal glands, or they originate from peripheral conversion of androgen precursor. Each of the three principal compartments of androgen production has a serum specific marker that may be clinically helpful. Serum testosterone signifies ovarian production, dehydroepiandrosterone sulfate (DHA-S) is an adrenal marker, and serum 3 alpha-diol glucuronide reflects androgen action in the peripheral compartment. Many physiologic and pathologic states affect transport proteins and enzyme systems which modulate androgenic activity...
March 1996: Lijec̆nic̆ki Vjesnik
https://read.qxmd.com/read/8737416/steroid-metabolizing-enzymes-in-pluripotential-progenitor-central-nervous-system-cells-effect-of-differentiation-and-maturation
#40
JOURNAL ARTICLE
R C Melcangi, P Froelichsthal, L Martini, A L Vescovi
A novel in vitro system which allows extensive culturing of multipotential stem cells from mouse brain has made it possible to test whether enzymes that metabolize androgens and progestagens are present in undifferentiated central nervous system progenitor cells. Embryonic day 14 striatal cells were grown in the presence of either 20 ng/ml of epidermal growth factor (which prevents cell differentiation), or 2% fetal bovine serum (facilitating differentiation). Differentiation was complete by 35 days in vitro when the cell population comprised 86 +/- 2...
May 1996: Neuroscience
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