Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ANDROSTERONE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources
PubMed1983

Glucosiduronidation of androsterone by human breast tumors in vitro in relation to the progesterone receptor content.

Homogenates of human breast tumors were incubated with 3H-androsterone and the percentage conversions to androsterone glucosiduronate were determined. In addition, separate portions of the tumors were analyzed for estrogen receptor (ER) and progesterone receptor (PR) to see whether conjugation and receptor content could be correlated. Sixteen of thirty-two tumor homogenates formed androsterone glucosiduronate (0.03-5.9%) from androsterone. There was no correlation between ER content and glucuronyltransferase activity. Considering the twenty-six malignant mammary tumors, of the fifteen PR positive types, five (one-third) formed the conjugate. In contrast, almost two-thirds (seven of eleven) of the PR negative tumors formed androsterone glucosiduronate. These correlations indicate a trend, but not of statistical significance.

Androsterone↗
PubMed1982

Developmental alteration of hepatic UDP-glucuronosyltransferase and sulphotransferase towards androsterone and 4-nitrophenol in Wistar rats.

Postnatal development of hepatic UDP-glucuronosyltransferase and sulphotransferase activities towards androsterone and 4-nitrophenol as well as cytochrome P-450 contents was studied in male and female Wistar rats. The rats with high and low UDP-glucuronosyltransferase activity towards androsterone were classified by the genotype of the parent animals. UDP-glucuronosyltransferase activity towards androsterone began rapidly to enhance after 30 days of age in the high-activity group, whereas the transferase activity remained low throughout in the low-activity group. Such a striking difference was not observed in UDP-glucuronosyltransferase activity towards 4-nitrophenol, sulphotransferase activity towards androsterone and 4-nitrophenol, and cytochrome P-450 contents. Sex-based difference in the sulphotransferase activity was marked after 30 days of age. Sulphotransferase activity towards androsterone was much higher in adult females than in adult males, whereas higher sulphation activity towards 4-nitrophenol was found in adult males. The results also indicate that the low level of the UDP-glucuronosyltransferase activity did not lead to compensatory stimulation of the sulphotransferase activity.

Age Factors↗
PubMed1996

Serum androsterone levels in children.

Serum androsterone was measured by radioimmunoassay in 79 girls and 80 boys aged between six months to sixteen years. In boys, androsterone levels were found to be low until the age of 12 years and then rapidly increased between the ages of 12-13 years. This increase of serum androsterone in boys seems to be related to the rapid increase of testosterone. On the other hand, in girls the androsterone levels were found to be low until the age of 10 years. However, from this age onwards, although individual values were variable, androsterone levels did not increase as rapidly as in boys but rather gradually with age which appeared to be influenced by the progressive increase of dehydroepiandrosterone (DHEA) in girls.

Adolescent↗
PubMed1975

Identification and measurement of urinary estrone, estradiol-17 beta, estriol, pregnanediol and androsterone during the menstrual cycle of the orangutan.

Urinary estrone, estradiol-17beta, estriol, pregnanediol and androsterone were identified and measured during 3 menstrual cycles in 2 female orangutans. In 2 of the cycles, the animals excreted 1-8 mug/day estrone, 0.5-6 mug/day estradiol-17beta, 1-8 mug/day estriol, 20-206 mug/day pregnanediol and 120-522 mug/day androsterone during the first half of the menstrual cycle. In the second half of the cycle, corresponding values were 3-21 mug/day estrone, 2-10 mug/day estradiol-17beta, 1-9 mug/day estriol, 54-800 mug/day pregnanediol and 90-1158 mug/day androsterone. In 1 cycle, the estrogen values for the second half were considerably higher, possibly due to the animal becoming pregnant just before this study commenced. The values for estrone and estradiol-17beta are similar to those found in the human and chimpanzee menstrual cycle. The values for estriol were lower than in the human but higher than in the chimpanzee. Levels for urinary pregnanediol and androsterone were significantly lower than in the human. Variations during the menstrual cycle for estrone were characterized by a midcycle peak followed by a second peak in the luteal phase. No definite pattern was apparent for estradiol-17beta or estriol. Both urinary pregnanediol and androsterone levels were low during the first half of the cycle, started to rise just after midcycle, and showed a peak during the second half of the menstrual cycle.

Androsterone↗
PubMed1977

The metabolism and 24-hour plasma concentrations of androsterone in man.

A radioimmunoassya for free androsterone permitting facile analysis of plasma taken at 20 min intervals over 24 h has revealed a curve of varying concentrations which formed a pattern similar to curves of cortisol and dehydroisoandrosterone, boht bein primary adrenal secretory products and the latter being the major precursor of androsterone. The mean of the average 24 h concentrationof androsterone in men was 55 +/- 14 ng/dl (n = 8). Such temporally related behavior requires rapid production and removal of both 17-ketosteroids, processes which have been confirmed by tracer studies where it has been shown that in a two compartment system, androsterone has a t1/2 of 25 +/- 9 min for the fast component and metabolic clearance rate of 4050 +/- 1315 L per day (n = 10). The data are in accord with an approximate production rate of androsterone which is consistent with values reported for its urinary excretion.

Androsterone↗
PubMed1993

Androsterone sulfate: physiology and clinical significance in hirsute women.

Androsterone sulfate (Andros-S) is the most abundant 5 alpha-reduced androgen metabolite in serum. To determine whether this steroid could serve as a marker of 5 alpha-reductase activity, we developed a specific RIA, using tritiated Andros-S to assess procedural losses. Baseline serum Andros-S levels (mumol/L; mean +/- SEM) in 14 hirsute women (3.0 +/- 0.4) were not reduced by ovarian suppression with leuprolide (3.0 +/- 0.3), but were decreased by 79% with combined ovarian and adrenal suppression with leuprolide and dexamethasone. The mean Andros-S level in polycystic ovarian syndrome (3.2 +/- 0.4) and in idiopathic hirsutism (3.5 +/- 0.5) was not significantly different from levels in normal women (3.0 +/- 0.5), but were significantly greater than levels in obese women (1.7 +/- 0.3; P < 0.05). The serum concentrations of Andros-S were about 10-fold greater than those of androsterone glucuronide and 100-fold greater than those of androstanediol glucuronide. Serum Andros-S concentrations correlated strongly with dehydroepiandrosterone sulfate (R = 0.59; P < 0.001) and to a lesser degree with androstanediol glucuronide and androsterone glucuronide (R = 0.28 and 0.49, respectively). There was a weak correlation with androstenedione levels and the androstenedione response to ACTH (R = 0.38 and 0.34, respectively), and no significant correlation with serum testosterone (R = 0.19). The ratio of any of the 5 alpha-reduced products (Andros-S, androstanediol glucuronide, and androsterone glucuronide) to precursors (androstenedione and testosterone) was not increased in hirsute women, suggesting that these women did not have a generalized increase in 5 alpha-reductase activity. In conclusion, these results confirm that Andros-S is the most abundant 5 alpha-reduced androgen metabolite in serum. It is primarily, if not exclusively, of adrenal origin in hirsute women. The fact that its levels were not elevated in hirsutism, although those of other adrenal androgens and androgen metabolites (androstanediol glucuronide and androsterone glucuronide) were, suggests that variations in sulfotransferase activity or metabolic clearance of Andros-S may be important determinants of serum Andros-S levels. Although Andros-S may be a marker of systemic 5 alpha-reductase activity, there was no evidence of a generalized increase in 5 alpha-reductase activity in hirsute women. Andros-S is therefore not recommended as a marker of either adrenal androgen production or of hirsutism.

17-alpha-Hydroxyprogesterone↗
PubMed1979

Production of testosterone, 5 alpha-androstane-3 alpha, 17 beta-diol and androsterone by dispersed testicular interstitial cells and whole testes in vitro.

The production of 5 alpha-androstane-3 alpha, 17 beta-diol (androstanediol), androsterone and testosterone by whole rat testes and testicular interstitial cells dispersed with collagenase was studied in vitro. Luteinizing hormone stimulated the production of each of the androgens by cells prepared from 31- to 34-day-old rats. Half maximum stimulation of the production of each androgen occurred with approximately 3.5 ng NIH-LH-B9/ml medium. Androstanediol was the predominant product then androsterone and then testosterone. Luteinizing hormone stimulated the production of testerone, but not androstanediol or androsterone by dispersed interstitial cells from 200-day-old rats. The time-course of production and the effect of the concentration of cells on the production of these androgens suggested that in dispersed testicular interstitial cells from immature animals androstanediol and androsterone are formed, at least partially, by the metabolism of testosterone. In these experiments LH-stimulated testosterone production increased during incubation for 15--60 min and then remained constant up to 180 min. The concentrations of androstanediol and androsterone increased in a linear manner during incubation for 60--180 min. Varying the number of cells incubated yielded a positive correlation between cell concentration and the ratio 5 alpha-reduced androgen : testosterone produced. Luteinizing hormone stimulated production of each androgen by whole tests obtained from rats at 30--175 days of age. The serum concentration of testosterone in these rats increased abruptly at 50 days of age. Significant changes in androgen production in vitro also observed at this age included: (1) increased production of the three steroids when incubated in either the presence or absence of LH and (2) testosterone production, either in the presence or absence of LH, which represented a greater percentage of the total production of the three androgens.

Age Factors↗
PubMed1969

Conjugation of androsterone by the guinea-pig kidney in vitro.

Radioactive androsterone was incubated with kidney slices from guinea pigs in a Ringer bicarbonate buffer. For analysis, the radioactivity was partitioned between chloroform and water for the separation of non-polar and polar steroids. After multiple chromatography procedures, the non-polar fraction was shown to contain androsterone and at least four other similar steroids, not identified in this study. The polar fraction yielded numerous conjugates from which androsterone glucuronide and androsterone sulphate in approximately equal quantities were isolated and characterized.

Androsterone↗
PubMed1979

Strain differences in rat liver (UDP-glucuronyltransferase activity towards androsterone.

Male Donryu, Wistar King rats showed discontinuous variations in hepatic microsomal UDP-glucuronyltransferase activities towards androsterone, but not towards testosterone, bilirubin, phenolphthalein and 4-nitrophenol. Fresh microsomal fraction with a low transferase activity towards androsterone formed 0.049--0.080 nmole of glucuronide/min per mg of protein, whereas fresh microsomal fraction with a high transferase activity towards androsterone formed 0.335--0.557 nmol of glucuronide/min per mg of protein. The microsomal fraction with low enzyme activity towards androsterone was not stimulated by treatment with Triton X-100 or freezing and thawing. In contrast, male Long Evans and Sprague-Dawley rats did not exhibit such diversity.

Androsterone↗
PubMed1984

Effects of steroid hormones and xenobiotics on the pubertal development of UDP-glucuronosyltransferase activities towards androsterone and 4-nitrophenol in Wistar rats.

Oestradiol benzoate, testosterone propionate, progesterone, corticosterone, 3-methylcholanthrene and phenobarbital were administered to Wistar rats at the pubertal period, and their effects on hepatic UDP-glucuronosyltransferase activities were determined. Pretreatment with oestradiol benzoate had a temporary suppressive effect on androsterone UDP-glucuronosyltransferase activity in rats with the high-activity phenotype of androsterone glucuronidation. The effect was marked in 40-day-old rats, but was not found in older rats. Androsterone UDP-glucuronosyltransferase activity was induced by phenobarbital in rats with the high-activity phenotype, but not in rats with the low-activity phenotype. Foster-feeding experiments showed that breast milk did not alter the genetically determined expression of androsterone UDP-glucuronosyltransferase activity in Wistar rats. In contrast, 4-nitrophenol UDP-glucuronosyltransferase activity was not affected by steroid hormones, but was highly induced by 3-methylcholanthrene.

Androsterone↗
PubMed1977

Serum 5alpha-androstane-3alpha,17beta-diol, androsterone, and testosterone concentrations in the male rat. Influence of age and gonadotropin stimulation.

Serum concentrations of testosterone plus dihydrotestosterone (T-DHT), 5 alpha-androstane-3 alpha, 17 beta-diol (Diol) and androsterone were measured during sexual maturation in male rats. Diol concentrations of 1 to 2.25 ng/ml were found in animals 10-90 days of age with no significant changes. Diol was the major androgen (5.75-8 times T-DHT) from age 20-40 days. Androsterone rose to 1.25 ng/ml at 25 days of age and declined to values of greater than 0.5 ng/ml from age 30-90 days. Testosterone-DHT levels were 1 ng/ml or less from 10-40 days of age, and then rose to a peak at 60 days. The ratio of Diol toT-DHT was significantly elevated from age 20-35 days, indicating that Diol is the major androgen in circulation at this time. Acute treatment of 33 day old rats with LH, but not with FSH, resulted in a dose-dependent increase in serum T-DHT, Diol, and androsterone. The dose-response and time course of response for the three steriods were nearly identical. Changes in testes capacity to secrete androgens were assessed 25, 33, 40 and 60 days of age by administering a maximum dose of LH before blood collection. Maximum response (sum of androsterone, Diol and T-DHT) occurred at 40 days with no further increase at 60 days.

Aging↗
PubMed1976

Response of plasma testosterone, urinary 17-oxosteroids, oestrogens, and androsterone plus aetiocholanolone to human chorionic gonadotrophin in dexamethasone-suppressed men.

The administration of human chorionic gonadotrophin (HCG) to dexamethasone-suppressed men caused parallel changes in the concentration of plasma testosterone and in the urinary output of androsterone+aetiocholanolone, total 17-oxosteroids and oestrogens. Discrepant results occurred in only four of the thirty-seven men tested. With these exceptions, the response to HCG could by followed as well by measuring androsterone+aetiocholanolone, 17-oxosteroid or oestrogen excretion rates as by following plasma testosterone levels. The most sensitive index of response was the rate of appearance of oestrogens in urine, and the next that of androsterone+aetiocholanolone.

17-Ketosteroids↗
PubMed1990

Androsterone glucuronide is a marker of adrenal hyperandrogenism in hirsute women.

Androsterone glucuronide (Andros-G), a dihydrotestosterone metabolite, is present in serum at concentrations at least tenfold greater than those of androstanediol glucuronide. To investigate the significance of serum androsterone glucuronide, we developed a direct radioimmunoassay for this compound and measured its levels in normal women, women with mild or severe idiopathic hirsutism (IH), hirsute women with polycystic ovarian syndrome (PCO), and non-hirsute obese women. To determine the source of Andros-G precursors, serum levels were measured before and after selective ovarian suppression with leuprolide, combined ovarian and adrenal suppression with leuprolide and dexamethasone, and adrenal stimulation with ACTH. Androsterone glucuronide levels (nmol/l; mean +/- SD) were significantly higher (P less than 0.025) in women with mild idiopathic hirsutism (IH) (185 +/- 91), severe IH (173 +/- 97), and hirsute women with polycystic ovarian syndrome (PCO) (178 +/- 102) than in normal women (110 +/- 26). Levels in non-hirsute obese women (64 +/- 19) were lower than in normal women (P less than 0.01). Baseline levels (mean +/- SEM) in hirsute women given 20 micrograms/kg/day leuprolide for 5-9 months (171 +/- 15) were not significantly changed after leuprolide alone (153 +/- 18), and were decreased after adding dexamethasone (19 +/- 6; P less than 0.001). Andros-G levels did not increase significantly in normal women 60 min after i.v. ACTH (112 +/- 14 to 126 +/- 19), but rose in IH (170 +/- 24 to 216 +/- 26; P less than 0.001) and in PCO (179 +/- 26 to 238 +/- 31; P = 0.002). We conclude that Andros-G in women arises primarily from adrenal gland precursors and is elevated in hirsute women as a group. Its levels do not correlate with the severity of hirsutism, or the presence or absence of PCO, but reflect an increased production of adrenal androgens in both IH and PCO.

Adrenal Glands↗
PubMed1976

Androsterone sulfate concentrations in plasma in hypo- and hyperthyroidism.

Androsterone sulfate concentrations have been measured in the plasma of 16 hypothyroid women and 14 hyperthyroid women by a gas-liquid chromatographic technique and in 23 hypothyroid and 18 hyperthyroid women by radioimmunoassay. In obth studies androsterone sulfate concentrations were significantly higher in the hyperthyroid groups. In one hypothyroid subject, blood was obtained at 20-minute intervals over 24 hours before and after the administration of triiodothyronine; plasma androsterone sulfate, initially 25 mug per dl, increased three-fold as a consequence of treatment.

Adult↗
PubMed1978

Subnormal tissue 3 alpha-androstanediol and androsterone in prostatic hyperplasia.

We investigated the role of 3 alpha-androstanediol (3 alpha-diol) in the development of benign prostatic hyperplasia (BPH) and the apparent equilibrium of enzymes which metabolize it in normal and hyperplastic prostatic tissue of humans. We determined the endogenous concentrations of 3 alpha-diol, androsterone, its 3 alpha-17-keto metabolite or precursor, and 5 alpha-dihydrotestosterone (DHT), its 3-keto,17 beta-hydroxy product of precursor, by RIA after extraction and paper chromatography of the androgens from normal and hyperplastic prostate glands. The mean concentrations of 3 alpha-diol and androsterone were about one-third of normal in BPH. The mean ratio of the concentration of DHT to 3 alpha-diol was significantly higher (P less than 0.005) than normal in BPH, whereas no statistical difference was observed for the mean ratio of the tissue levels of 3 alpha-diol to androsterone in the two groups. Our data do not support the postulate that 3 alpha-diol is causally related to the development of BPH. However, they indicate that the apparent equilibrium of the 3 alpha-hydroxysteroid oxidoreductase favors the formation of the 3-keto-oxidized product, DHT, which may have relevance to the occurrence of the renewed growth of the prostate of aging men.

Androgens↗
PubMed1983

Concentrations of testosterone and androsterone in peripheral and umbilical venous plasma of fetal rats.

Mean +/- s.d. testosterone concentrations in the peripheral plasma of 21- and 22-day-old male fetuses (1.32 +/- 0.43 ng/ml) were significantly (P less than 0.05) higher than those in the umbilical venous plasma (0.37 +/- 0.08 ng/ml). Testosterone concentrations in umbilical venous plasma of male and female (0.29 +/- 0.06 ng/ml) fetuses and in peripheral plasma of female fetuses (0.36 +/- 0.10 ng/ml) were not significantly different. Androsterone levels measured in umbilical venous plasma of male (11.5 +/- 2.5 ng/ml) and female (12.3 +/- 2.1 ng/ml) fetuses were nearly as high as those in peripheral plasma (males, 12.9 +/- 3.1; females, 13.3 +/- 3.5 ng/ml). There were high concentrations of androsterone in the placentas of male (33 +/- 4 ng/g) and female (33 +/- 5 ng/ml) fetuses, suggesting that this organ is the major source of fetal androsterone. We also conclude that a major part of the testosterone present in female fetuses is secreted by the placentas.

Androsterone↗
PubMed1996

Growth hormone stimulates androsterone synthesis by rat theca-interstitial cells.

The aim of this study was to assess the possible role of growth hormone (GH) on androsterone synthesis. This effect was analyzed in theca-interstitial cells obtained from immature female rats. The addition of GH to the cultures significantly stimulated androsterone (A) synthesis in a dose- and time-dependent way and this effect was not due to a cellular number increase. When added to the hCG cultures, GH significantly enhanced androgen production even though it did not synergyze with the chorionic gonadotropin. The addition of antibodies anti-IGF-I to the GH cultures did not modify the growth hormone effect suggesting that GH probably does not require IGF-I to achieve its effect on A production. Finally, no effect of GH on cAMP levels were observed in the cultures at the end of the treatment. Our results demonstrate that GH is able to significantly induce A synthesis by rat theca-interstitial cells. Since the presence of GH and its receptors in the ovary is now well established the present data strongly suggest a potential relevance of GH in reproductive biology.

Androsterone↗
PubMed2002

Diurnal variation in the proconvulsant effect of 3-mercaptopropionic acid and the anticonvulsant effect of androsterone in the Syrian hamster.

GABA is the principal neurotransmitter of the mammalian circadian system, and its activity is subject to diurnal and circadian variations, with maximal values in hypothalamic turnover, content and binding during the night. In this study we have examined rhythms in the proconvulsant effect of inhibition of glutamate decarboxylase (GAD) in hamsters (Mesocricetus auratus) as well as the anticonvulsant effect of androsterone, a neurosteroid that positively modulates the GABA(A) receptor. Administration of 10-60 mg/Kg of 3-mercaptopropionic acid (3-MPA, a GAD inhibitor) induced convulsions that were analyzed by an ad-hoc severity scale, with a lower sensitivity threshold at 24:00 h. Moreover, the latency for first and maximal convulsive response times was significantly lower at night. A similar temporal profile (maximal effect at midnight) was found for picrotoxin-induced seizures. Androsterone (40 mg/Kg) completely inhibited 3-MPA-induced tonic/clonic seizures at 12:00 h, while it had a partial inhibitory effect at 24:00 h. These results support the importance of temporal regulation of GABAergic modulation in the central nervous system.

3-Mercaptopropionic Acid↗