Abstract:
:Steroid hormones can differentially modify gonadotropin release stimulated by GnRH. Decreased GnRH-mediated gonadotropin release has been observed in vitro after pretreatment with androgens or glucocorticoids. In this study, we tested this phenomenon further with the use of a new cytochemical stain for a potent biotinylated analog of GnRH ([Biotinyl D-Lys6]GnRH) combined with stains for LH and FSH and gonadotropin RIAs. The first phase of the study involved characterization of the GnRH target cells in monolayer cultures from male rats. Dose-response curves (measured as the ability to release both LH and FSH) showed that biotinylated GnRH (Bio-GnRH) was equipotent with or more potent than unlabeled [D-Lys6]GnRH in parallel cultures. The avidin-biotin complex stain demonstrated that 16% of the 2- to 3-day pituitary monolayer cells were labeled for Bio-GnRH within 10 min of exposure. Double stains for gonadotropins showed that 37% of the LH gonadotropes and 42% of the FSH gonadotropes did not stain for Bio-GnRH. During the second phase of these studies, the cultures were pretreated for 48 h with 1-100 nM 5 alpha-dihydrotestosterone (DHT), 100 nM corticosterone (CT), or 100 nM epitestosterone (ET) to test the effects of these steroids on the number of cells to which Bio-GnRH bound and the gonadotrope secretory response. Compared with ET- or vehicle-pretreated control cultures, DHT and CT both reduced the amount of LH and FSH release stimulated by GnRH. The magnitude of the reduction in LH release was much greater than that in FSH release, especially after pretreatment with CT. DHT and CT had remarkably different effects on the percentages of cells stained for GnRH. Pretreatment with DHT caused a reduction in the percentages of cells staining for bound Bio-GnRH to 9% compared with 14.3% after CT treatment and 16% after vehicle or ET treatment. The counts of the stained gonadotropes suggested that most of the reduction occurred in the LH gonadotrope population. Because both DHT and CT reduced GnRH-mediated gonadotropin release, but only DHT reduced the percentage of cells that bound Bio-GnRH, it is suggested that the two steroids affect gonadotropin release by separate mechanisms.
journal_name
Endocrinologyjournal_title
Endocrinologyauthors
Tibolt RE,Childs GVdoi
10.1210/endo-117-1-396subject
Has Abstractpub_date
1985-07-01 00:00:00pages
396-404issue
1eissn
0013-7227issn
1945-7170journal_volume
117pub_type
杂志文章相关文献
ENDOCRINOLOGY文献大全abstract::3 beta-Hydroxy-5-ene-steroid dehydrogenase/delta 5-delta 4-isomerase (3 beta HSD) is a NAD(+)-dependent membrane-bound enzyme that catalyzes the oxidation of delta 5-3 beta-hydroxysteroids to delta 4-3-keto structures during adrenal, gonadal, and placental steroidogenesis. Enzyme activity is located in both microsomes...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.134.2.8299570
更新日期:1994-02-01 00:00:00
abstract::GH is an important regulator of body growth and composition as well as numerous other metabolic processes. In particular, liver plays a key role in the GH/IGF-I axis, because the majority of circulating "endocrine" IGF-I results from GH-stimulated liver IGF-I production. To develop a better understanding of the role o...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2013-2086
更新日期:2014-05-01 00:00:00
abstract::We investigated the effect of epidermal growth factor (EGF) on collagen and protein synthesis in clone MC3T30-E1, a cell line which retains osteoblast-like characteristics. EGF at concentrations of 2-50 ng/ml significantly the hydroxyproline content of the cell layer. These effects were completely abolished by the add...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-111-6-1810
更新日期:1982-12-01 00:00:00
abstract::The distribution and density of selectively labeled mu-, delta-, and kappa-opioid binding sites were examined by in vitro radioautography in the hypothalamus of normal, estradiol valerate (EV)-injected, and estradiol (E2)-implanted female rats. Hypothalamic beta-endorphin concentration was also examined by RIA in thes...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-127-6-2969
更新日期:1990-12-01 00:00:00
abstract::The steroid hormone 1 alpha,25-dihydroxyvitamin D3 [1,25-(OH)2D3] can elicit biological responses via a nongenomic pathway that involves rapid opening of the plasma membrane Ca2+ channels. There is also evidence that 1,25-(OH)2D3 influences insulin secretion in the pancreatic beta-cell, which is primarily mediated by ...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.136.7.7789310
更新日期:1995-07-01 00:00:00
abstract::The thyroid hormone (TH) analog eprotirome (KB2115) was developed to lower cholesterol through selective activation of the TH receptor (TR) β1 in the liver. Interestingly, eprotirome shows low uptake in nonhepatic tissues, explaining its lipid-lowering action without adverse extrahepatic thyromimetic effects. Clinical...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2017-00433
更新日期:2017-10-01 00:00:00
abstract::Two experiments tested whether serotonergic neurons participate in the acute feedback effects of estradiol on LH and PRL secretion. In the first study, ovariectomized female rats received oil vehicle or estradiol benzoate and were killed 3 h later. The turnover of serotonin [5-hydroxytryptamine (5-HT)] in microdissect...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-113-6-1935
更新日期:1983-12-01 00:00:00
abstract::Task3 K(+) channels are highly expressed in the adrenal cortex and contribute to the angiotensin II and K(+) sensitivity of aldosterone-producing glomerulosa cells. Adult Task3(-/-) mice display a partially autonomous aldosterone secretion, subclinical hyperaldosteronism, and salt-sensitive hypertension. Here, we inve...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2013-1101
更新日期:2013-08-01 00:00:00
abstract::Activin, a member of the transforming growth factor-beta superfamily, binds to two classes of cell surface receptors. These receptors, designated type I and type II, are structurally related members of transmembrane serine kinase superfamily. Antibodies specific for either type I or type II activin receptor can coprec...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.136.12.7588300
更新日期:1995-12-01 00:00:00
abstract::Bone remodeling is a complex process of coordinated resorption and formation of bone, which is regulated by systemic hormones and by local factors. We have previously shown that the peptide hormone adrenomedullin is mitogenic to osteoblastic cells in vitro and that it promotes bone growth in vivo. The aim of the prese...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.142.5.8152
更新日期:2001-05-01 00:00:00
abstract::3-Iodothyronamine (T(1)AM) is an endogenous thyroid hormone derivative with unknown biosynthetic origins. Structural similarities have led to the hypothesis that T(1)AM is an extrathyroidal metabolite of T(4). This study uses an isotope-labeled T(4) [heavy-T(4) (H-T(4))] that can be distinguished from endogenous T(4) ...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2012-1254
更新日期:2012-11-01 00:00:00
abstract::Impaired wound healing of skin is one of the most serious complications of diabetes. However, the pathogenesis of this process is not known, and it is unclear whether impaired insulin signaling could directly affect skin physiology. To elucidate the role of insulin in skin, we studied skin insulin receptor (IR) null m...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.142.3.7988
更新日期:2001-03-01 00:00:00
abstract::Ghrelin is more effective than GHRH in stimulating GH release in normal adult humans and monkeys in vivo. This robust effect of ghrelin has been largely attributed to regulation of hypothalamic input, whereas the direct effect of ghrelin on pituitary GH release has been minimized by the observation that ghrelin has on...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2007-0441
更新日期:2007-09-01 00:00:00
abstract::Periconceptional undernutrition (PCUN) results in an earlier prepartum activation of the pituitary-adrenal axis in twin compared with singleton fetuses. We have tested the hypotheses that the functional development of the fetal sheep adrenal is delayed in twins compared with singletons in early gestation and that PCUN...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2006-0761
更新日期:2007-04-01 00:00:00
abstract::Exercise has a potent insulin-sensitivity enhancing effect on skeletal muscle, but the intracellular mechanisms that mediate this effect are not well understood. In muscle, Ras-related C3 botulinum toxin substrate 1 (Rac1) regulates both insulin- and contraction-stimulated glucose transport and is dysregulated in insu...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2016-1220
更新日期:2016-08-01 00:00:00
abstract::We previously identified a highly conserved specificity protein 1 (Sp1) DNA element in mammalian PTH promoters that acted as an enhancer of gene transcription and bound Sp1 and Sp3 proteins present in parathyroid gland nuclear extracts. More recently, a nuclear factor (NF)-Y element (NF-Y(prox)) was also described by ...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2005-0272
更新日期:2005-08-01 00:00:00
abstract::Adult female transgenic mice expressing the human GH (hGH) gene with mouse metallothionein-I promoter are sterile. To evaluate the hypothalamic-pituitary function in these animals, adult female transgenic mice and nontransgenic normal littermates were ovariectomized. On days 7 and 8 after ovariectomy, mice were inject...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.130.4.1547710
更新日期:1992-04-01 00:00:00
abstract::The effect of gonadotropins on phosphodiesterase activity of rat granulosa cells was studied in an in vitro model. Granulosa cells were prepared from hypophysectomized or intact, estrogen-primed immature female rats and treated with FSH, hCG, or (Bu)2cAMP in vitro. Phosphodiesterase activity was determined in cell hom...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-114-6-2361
更新日期:1984-06-01 00:00:00
abstract::Aromatase-deficient (ArKO) mice are deficient in estrogens due to deletion of the aromatase gene. We hypothesized that there may be changes in the cardiovascular system of ArKO mice because of evidence linking estrogens with improved cardiovascular outcomes and the induction of the glucocorticoid-metabolizing enzyme, ...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2004-0421
更新日期:2004-09-01 00:00:00
abstract::Arterial pressure (AP), heart rate (HR), and cardiovascular diseases, including ischemic heart attack and cerebrovascular accident, show diurnal variation. Evidence that circadian-related genes contribute to cardiovascular control has been accumulated. In this study, we measured the AP and HR of Clock mutant mice on t...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2007-1714
更新日期:2008-07-01 00:00:00
abstract::There is a growing body of evidence that subtle decreases in maternal thyroid hormone during gestation can impact fetal brain development. The present study examined the impact of graded levels of thyroid hormone insufficiency on brain development in rodents. Maternal thyroid hormone insufficiency was induced by expos...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2006-1276
更新日期:2007-06-01 00:00:00
abstract::Diastolic dysfunction is a prognosticator for future cardiovascular events that demonstrates a strong correlation with obesity. Pharmacological inhibition of dipeptidylpeptidase-4 (DPP-4) to increase the bioavailability of glucagon-like peptide-1 is an emerging therapy for control of glycemia in type 2 diabetes patien...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2013-1096
更新日期:2013-07-01 00:00:00
abstract::The previously reported synchronous oscillations in plasma glucose and insulin levels have been further studied to determine whether the phenomenon can be attributed to cyclic secretion or degradation of the hormone. Plasma C-peptide concentrations were measured and found to cycle with the same period as plasma insuli...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-102-5-1649
更新日期:1978-05-01 00:00:00
abstract::Prokineticin-1 (PK1) is a recently described protein with a wide range of functions, including tissue-specific angiogenesis, modulation of inflammatory responses, and regulation of hemopoiesis. The aim of this study was to investigate the localization and expression of PK1 and PK receptor-1 (PKR1), their signaling pat...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2007-1695
更新日期:2008-07-01 00:00:00
abstract::GH is believed to play a role in promoting insulin resistance in patients with diabetes and with GH excess. The means by which GH produces insulin resistance may be through direct suppression of glucose metabolism in target cells (insulin-independent) or by interfering with the ability of insulin to stimulate glucose ...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-123-2-1082
更新日期:1988-08-01 00:00:00
abstract::Interleukin (IL)-10 is a highly important anti-inflammatory cytokine in the immune system. CD1dhi and CD5+ B cells are both traditionally defined IL-10-secreting B cells. In recent years, a B cell group with combined markers of CD1dhi and CD5+ has been widely studied as it has been reported to suppress autoimmunity in...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endocr/bqaa033
更新日期:2020-04-01 00:00:00
abstract::FSH promotes the differentiation of ovarian follicular granulosa cells via a cAMP-dependent mechanism. Based upon the presence of a prominent phospholipid/diolein/Ca2+-independent myelin basic protein kinase activity in soluble extracts of proliferating immature rat granulosa cells, we determine whether this activity ...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.137.3.8603610
更新日期:1996-03-01 00:00:00
abstract::Somatostatin (SRIF) inhibits vasoactive intestinal peptide (VIP)-stimulated cAMP accumulation in the GH4C1 strain of rat pituitary tumor cells, and this effect is responsible for SRIF inhibition of VIP-stimulated hormone release. In this study we examined the interaction between the SRIF receptor and adenylate cyclase...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-114-5-1784
更新日期:1984-05-01 00:00:00
abstract::Endocannabinoids act as a major neuromodulatory system in a variety of physiological and behavioral functions. Three major lines of evidence suggest that the endocannabinoid system interacts with gonadal hormones. First, the endocannabinoid system is implicated in behaviors and physiological functions that are known t...
journal_title:Endocrinology
pub_type: 杂志文章,评审
doi:10.1210/en.2011-1643
更新日期:2012-03-01 00:00:00
abstract::Inhibins and activins are produced by a variety of tissues and may have important endocrine and paracrine roles in development, reproduction, and hematopoiesis. However, little is known regarding the physical properties or concentrations of inhibin and activin in biological fluids. Binding proteins for inhibin or acti...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.132.1.7678220
更新日期:1993-01-01 00:00:00