Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of follicle-stimulating hormone (FSH) on cholesterol biosynthesis was studied using a recently developed serum-free medium for the culture of porcine granulosa cells. Both cell proliferation and progesterone production were shown to be dependent on de novo cholesterol synthesis in studies with an inhibitor of HMG-CoA reductase. Under basal conditions, mevalonate levels appeared to be rate-limiting for steroidogenesis but not for cell growth. FSH treatment increased [1-14C]acetate incorporation into sterols and the intracellular content of free and esterified cholesterol. These effect were not abolished when steroidogenesis was inhibited at the cholesterol side-chain cleavage step. Estradiol also stimulated [1-14C]acetate incorporation into sterols. Quantification of progesterone secretion after blockade of cholesterol synthesis revealed the presence of intracellular pools of precursor sterols which required depletion before progesterone secretion ceased. These pools, which were tentatively ascribed to cholesterol and pregnenolone, were increased in FSH-treated cells. Stimulation of cholesterol biosynthesis may play a fundamental role in FSH action on these cells.
Mol Cell Endocrinol 1986 Mar
PMID:FSH increases the synthesis and stores of cholesterol in porcine granulosa cells. 308 95

The present study was undertaken to investigate the effects of sex and estrous cycle on the manifestation of the extracellular Ca2+-independent component of gonadotropin secretion. Quartered pituitaries from male, ovariectomized (OVX) females +/- estradiol (E2) implants, and mature females at each stage of the estrous cycle were perifused with Ca2+-free medium. Gonadotropin releasing hormone (GnRH)-stimulated luteinizing hormone (LH) and follicle stimulating hormone (FSH) secretion from male and OVX pituitaries was inhibited in Ca2+-free medium. In contrast, only a partial inhibition was obtained from OVX + E2 or regularly cycling female pituitaries. This extracellular Ca2+-independent component of gonadotropin secretion was lowest at estrus and increased progressively during the estrous cycle. Estradiol replacement in OVX animals resulted in a response similar to that obtained on proestrus. These results indicate that the extracellular Ca2+-independent component of LH and FSH release is only manifest from intact female and not male pituitaries, and is dependent on estradiol.
Mol Cell Endocrinol 1988 Aug
PMID:Sex differences in the extracellular Ca2+-independent release of LH and FSH. 314 29

Estradiol-17 beta was previously shown to stimulate glucose transport (as measured by phosphorylation of 2-deoxyglucose) in rat uterine tissue in vivo (Meier, D.A. and Garner, C.W. (1987) Endocrinology 121, 1366-1374) but attempts to demonstrate this in uterine organ strips in vitro, in uterine tumor cell lines or in uterine cells in primary culture have been unsuccessful. However, aqueous uterine extracts and uterine luminal fluid did stimulate glucose transport in uterine tumor cells and uterine cells in primary culture. Estradiol in vivo and uterine extracts in vitro each increased the initial rate of glucose transport 1.5- to 3-fold. In each case, 2-3 h were required for the stimulation to be fully expressed. The stimulation was not inhibited by cycloheximide suggesting that protein synthesis was not required. Uteri from ovariectomized rats injected daily for 4 days with 10 micrograms estradiol contained 4-fold more activity than uteri from saline-injected control animals. The activity was acid- and heat-stable, inactivated by trypsin treatment but not removed by dextran-coated charcoal treatment, suggesting that the activity is (or is associated with) a protein. The activity eluted in the 6-12 kDa range upon chromatography on Sephadex G-50. Insulin (1-1000 ng/ml) and epidermal growth factor (1-100 ng/ml) stimulated glucose transport, but only less than 50% of the stimulation by extracts. The substance(s) present in the extracts, possibly a known growth factor, may be involved in the estradiol stimulation of glucose transport and other estradiol actions in vivo.
Mol Cell Endocrinol 1988 May
PMID:Stimulation of glucose transport in cultured uterine cells by rat and rabbit uterine extracts. 329 57

The effect of insulin in physiological concentrations on hormone secretion by human term trophoblast cell culture was studied in relation to insulin control of glucose transport and utilization. Specific inhibitors to these 2 functions were added to the culture, either alone to test for a dose response or with insulin. 2-Deoxy-D-glucose, which inhibits glycolysis, did not change the pattern of response of estradiol and placental lactogen (hPL) secretion to insulin. Phloridzin, an inhibitor of glucose transport, interfered with the stimulatory effect of insulin on hPL secretion, but stimulated insulin inhibition of estradiol secretion when added by itself. The results indicate that hPL response to insulin is dependent on glucose transport, but is independent of glycolysis. Estradiol response is dependent on glucose transport, but is independent of glycolysis.
Mol Cell Endocrinol 1985 Nov
PMID:The effect of inhibitors on insulin regulation of hormone secretion by cultured human trophoblast. 390 56

Estradiol is demonstrated to induce histidine decarboxylase, and histamine is shown to activate adenylate cyclase in rat uterus. Histamine and cyclic 3',5'-AMP mimic the effects of estradiol in that they enhance RNA synthesis, induce glycolytic enzymes and uterus imbibition. The data suggest that estradiol enhances by induction of histidine decarboxylase the formation of histamine, the latter activates adenylate cyclase providing accumulation of cyclic 3',5'-AMP, which, probably, induces glycolytic enzymes through phosphorylation of chromatin proteins, and mediates other estradiol effects. The chain of successively acting enzymes and mediators constitutes, obviously, a cascade amplifying estradiol action. Since histamine is known to act as an intercellular mediator, attempts were made to find out the distribution of estradiol histamine and cyclic 3',5'-AMP among uterus cells. Autoradiography has shown that [3H]-estradiol is bound by the nuclei of myometrium cells, [3H]-histamine was found above the cytoplasm of these cells, E13H]-cyclic 3',5'-AMP is selectively bound by the cells of capillary endothelium of the uterus. The estradiol mediators seem to spread effect of hormone on cells of different types which form together a kind of multicellular functional system.
Mol Cell Biochem 1980 Feb 28
PMID:Multistage functional system amplifying and spreading the effect of estradiol in rat uterus. 624 14

Dopamine levels were specifically increased in the intermediate lobe of the pituitary gland of ovariectomized rats following acute 17-beta-estradiol administration. Estradiol treatment increased the dopamine turnover rate 10-fold in the intermediate lobe and 2-fold in the posterior lobe of ovariectomized rats. In contrast, estrogen treatment had no effect on the endogenous levels or the turnover rate of norepinephrine in these tissues. Our results suggest that estrogens can selectively modulate dopamine metabolism in the posterior and intermediate lobes of the rat pituitary gland.
Cell Mol Neurobiol 1984 Dec
PMID:Estradiol increases dopamine turnover in intermediate and posterior pituitary lobes of ovariectomized rats. 653 24

The effect of a single injection of estradiol benzoate upon the activity of 17 alpha-hydroxylase and C17,20-lyase in the ovaries of hypophysectomized immature rats was investigated. Tritiated H2O from 17 alpha-[3H]progesterone and 14CH3COOH from 21-[14C]progesterone were the products measured to evaluate the hydroxylase and lyase activities respectively. Estradiol (E2) had no direct effect upon the activity of the enzymes in vitro even when present at twice the concentration of the substrate. However, when given in vivo, E2 reduced the activity of both enzymes. The ratio of the activities remained constant supporting the contention that both enzyme activities reside in one cytochrome P-450. Cycloheximide attenuated, but did not prevent, the reduction obtained with estrogen. Enzyme activities were reduced by E2 to a slightly lesser degree when the ovaries had been exposed in vivo to exogenous gonadotropin for 72 h. The results indicate that 17 alpha-hydroxylase and C17,20-lyase activities decrease when large doses of E2 are administered in vivo, that this effect is not directly on the enzymes, and that at least a part of this effect involves macromolecular synthesis.
Mol Cell Endocrinol 1984 May
PMID:The in vitro and in vivo effect of estradiol upon the 17 alpha-hydroxylase and C17,20-lyase activity in the ovaries of immature hypophysectomized rats. 661 May 82

The number of testosterone binding sites present in rat uterine cytosol varied regularly during the estrous cycle, reaching a trough at metestrus and a peak at proestrus. Treating ovariectomized and adrenalectomized rats for 2 days with estradiol resulted in a 3-4-fold increase in the number of binding sites per uterus. Estradiol withdrawal induced a decrease in uterine androgen receptors. Testosterone or progesterone treatment also increased the number of these sites, but to a lesser degree. When administered together with estradiol, testosterone did not enhance the stimulatory effect of the latter, whereas progesterone even reduced it. Testosterone or progesterone did not prevent the number of receptors from declining after estradiol withdrawal. Thus the changes in the number of cytoplasmic androgen receptors in the uterus during the rat estrous cycle is mainly controlled by the rise and fall of the serum levels of estradiol.
Mol Cell Endocrinol 1983 Mar
PMID:Variation of cytoplasmic rat uterine androgen receptors. 668 85

We have studied the hormonal control of prolactin (PRL) binding in the male rat sex glands and liver, subsequent to the recent demonstration and characterization of specific PRL binding sites in rat testis, prostate and seminal vesicle. Ovine PRL (200 micrograms/rat/day, 7 days) caused a time-dependent reduction in testicular binding of 125I-labelled PRL (measured 2 days after last injection) to 58% of control. Testosterone alone (1 mg/rat/day, 7 days) or PRL caused similar reductions in binding, while their coadministration further lowered PRL binding to 10% of control. The synergism of PRL and testosterone suggests that either these doses are submaximal, or that they are acting on different systems. Estradiol was administered as a single dose of 2 mg/rat and the PRL binding determined on day 10 and day 19 was reduced to 37% of control, as after testosterone. Addition of PRL whether from day 1 to day 7 or from day 11 to day 17 of estradiol injection had no effect, suggesting that the EB site of action is closer to the PRL receptor than that for PRL or testosterone. Estradiol resulted in a 72% reduction of PRL binding in the prostate, after 10 days, which subsequent PRL completely restored. PRL also partially restored the estradiol-induced time-dependent weight reduction of the prostate, but PRL coadministered from day 1 of estradiol did not inhibit the estradiol effects, suggesting a competitive mechanism for the two. While testosterone more than doubled PRL binding in the seminal vesicle, estradiol reduced it by 32% and organ weight by 21%. PRL given after estradiol restored the weight loss, but not the binding, suggesting that two different mechanisms of action are involved. In the liver, coadministration of testosterone with PRL could not inhibit the induction by PRL of its own hepatic sites, in keeping with a more direct site of action for PRL than for testosterone. These results demonstrate the profound effects of PRL, and of the sex steroids testosterone and estrogen, on PRL binding in the male sex glands and liver. The physiological implication of these findings on the role of PRL in male sexual function is currently being investigated.
Mol Cell Endocrinol 1983 May
PMID:Effect of prolactin, testosterone and estrogen on prolactin binding in the rat testis, prostate, seminal vesicle and liver. 685 62

MCF-7 cells contain progesterone, estradiol and glucocorticoid receptors. Following addition of these hormones to the growth medium of the cells, hormone-receptor complexes were found to sediment with chromatin fragments produced by trace digestion with micrococcal nuclease. The binding in all cases could be competed by excess unlabeled hormone. In each case the fragments with which the hormone-receptor complexes were associated tended to be smaller than the bulk chromatin fragments, indicating a greater sensitivity of those chromatin regions to the nuclease. The mononucleosomes released by more extensive digestion with micrococcal nuclease contained different amounts of each of the three hormone-receptor complexes. Progesterone could usually be detected on mononucleosomes only after very brief sedimentation analyses, whereas glucocorticoid- and estradiol-labeled mononucleosomes were stable during long centrifugations. Comparison of glucocorticoid- and estradiol-labeled mononucleosomes indicated that their sedimentation rates differed from one another and from bulk nucleosomes. Estradiol nucleosomes from MCF-7 cells and rat uterus (Senior and Frankel, 1978) sediment significantly faster than bulk nucleosomes, while glucocorticoid nucleosomes from MCF-7 cells and rat hepatoma cells sediment with, or even fractionally slower than, bulk nucleosomes.
Mol Cell Endocrinol 1983 Jun
PMID:Progesterone, glucocorticoid and estradiol receptors in MCF-7 cells bind to chromatin. 686 95


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>