Abstract:
:The ability of ovarian steroids to influence the release of LH was examined after ovariectomy in regularly cycling adult female rats and two types of anovulatory persistent estrous rats: rats treated with 10 mug of testosterone propionate (TP) shortly after birth, and normal rats housed under constant illumination. Two months after ovariectomy the negative feedback effects of a single injection of 20 mug estradiol benzoate (EB) on plasma LH were measured in these three preparations. Ovariectomized (ovex) normal and TP-treated but not ovex constant light-exposed rats had reduced LH values 6 hr after EB treatment. However, LH levels were reduced by the next day in rats in constant light. Positive feedback was measured in similar EB-primed rats following a second injection of EB or progesterone (P). In ovex normal rats LH values remained low in the morning but increased in the afternoon following the second steroid injection. Ovex EB-primed androgenized rats failed to demonstrate this positive feedback. Similarly, in ovex EB-primed constant light-exposed rats, LH values did not increase after a second EB injection. However, high LH values were observed in the afternoon 6 hr after P administration and again 40 and 50 hr later. These results indicate that the lack of spontaneous ovulation in androgenized rats may be due to the absence of positive feedback to ovarian steroids. Constant light-exposed ovex rats do not respond to the positive feedback action of estrogen and show a different response to P than ovex normal rats, in that a regular diurnal peak in plasma LH is not observed.
journal_name
Endocrinologyjournal_title
Endocrinologyauthors
Mennin SP,Gorski RAdoi
10.1210/endo-96-2-486subject
Has Abstractpub_date
1975-02-01 00:00:00pages
486-91issue
2eissn
0013-7227issn
1945-7170journal_volume
96pub_type
杂志文章相关文献
ENDOCRINOLOGY文献大全abstract::Inhibin was first characterized in mammals as a gonadal dimeric protein that inhibited pituitary follicle-stimulating hormone (FSH) secretion. As in mammals, the inhibin-specific α subunit (INHA/Inha/inha) has also been characterized in teleosts; however, its functions and physiological importance in fish reproduction...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endocr/bqaa184
更新日期:2020-12-01 00:00:00
abstract::Little is known about the mechanisms of action of polypeptide hormones on chromatin structure and nuclear function. We have employed micrococcal nuclease to examine the effect of TSH on the accessibility of DNA in thyroid nuclei. Brief digestion of nuclear suspensions with 0.05-0.2 U/ml micrococcal nuclease at 26-28 C...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-110-6-2118
更新日期:1982-06-01 00:00:00
abstract::The TSH receptor (TSHR) hinge region, the least well understood component, bridges the leucine-rich repeat and transmembrane domains. We report data on clusters of hinge charged residues the mutation of which to Ala is compatible with cell surface expression and normal, or near normal, TSH binding affinity yet with a ...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2012-1376
更新日期:2012-10-01 00:00:00
abstract::Brown adipose tissue (BAT) thermogenesis is activated by the sympathetic nervous system. BAT responses to norepinephrine are blunted in hypothyroidism and are rapidly restored by thyroid hormone. We examined in rats the effects of thyroid hormone on BAT beta 1- and beta 2-adrenergic receptors (AR) expression and capac...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.136.8.7628360
更新日期:1995-08-01 00:00:00
abstract::Mammary glands from second generation vitamin D-deficient mice and rats were examined for their ability to make the major milk proteins, casein and alpha-lactalbumin, both in vivo and in vitro. The glands from the rachitic animals were morphologically indistinguishable from those of age-matched controls. When placed i...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-121-3-865
更新日期:1987-09-01 00:00:00
abstract::Immunoreactive LHRH was detected in hypothalamic and extrahypothalamic brain extracts of the rat, bird (pigeon and chicken), reptile (tortoise and lizard), amphibian (frog and toad), teleost (cichid), and elasmobranch (dogfish) and in the whole brain of the cyclostome (bagfish). The concentration of hypothalamic immun...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-106-3-707
更新日期:1980-03-01 00:00:00
abstract::Experiments were carried out in castrate adult male rats to further examine whether endogenous opioids are involved in CRF-induced suppression of LH secretion. Serum LH levels in rats castrated 5 days earlier were significantly reduced by intracerebroventricular administration of homologous (rat) CRF (0.02-2 nmol) wit...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-122-3-1034
更新日期:1988-03-01 00:00:00
abstract::Circulating levels of the pancreatic beta-cell peptide hormone amylin and the gut peptide PYY[3-36] increase after nutrient ingestion. Both have been implicated as short-term signals of meal termination with anorexigenic and weight-reducing effects. However, their combined effects are unknown. We report that the combi...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2007-0898
更新日期:2007-12-01 00:00:00
abstract::GH is the major regulator of circulating IGF-I, which, in return, controls pituitary GH secretion by negative feedback. IGF-binding protein-1 (IGFBP-1) is believed to modify this feedback through its effects on free IGF-I. In the present study we investigated the potential influence of IGFBP-1 on GH secretion in the a...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2003-1742
更新日期:2004-09-01 00:00:00
abstract::Female rats were ovariectomized and either sham-pinealectomized or pinealectomized on day 24 of age and exposed to a photoperiod of 12 h light: 12 h dark. In vivo and in vitro measures of adrenocortical function were made at 6, 7, and 8 weeks of age (18, 25, and 32 days post-pinealectomy, respectively). Pinealectomy d...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-98-1-20
更新日期:1976-01-01 00:00:00
abstract::It is well established that in the pituitary gland corticotropin-releasing hormone (CRH) stimulates the release of beta-endorphin (beta-E) via a cAMP-linked mechanism. Studies of the mechanisms underlying the CRH stimulation of beta-E release from rat hypothalamic slices perifused in vitro are reported in this paper. ...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-125-3-1365
更新日期:1989-09-01 00:00:00
abstract::There is now general agreement that neurokinin B (NKB) acts via neurokinin-3-receptor (NK3R) to stimulate secretion of GnRH and LH in several species, including rats, mice, sheep, and humans. However, the roles of two other tachykinins, substance P (SP) and neurokinin A, which act primarily via NK1R and NK2R, respecti...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2016-1565
更新日期:2016-12-01 00:00:00
abstract::Recent studies from our laboratory demonstrated clearly that only a portion of all Sertoli cells secrete transferrin (TF). These findings raised the possibility that differences in the functional type of Sertoli cells from one location to another may account in part for the stage-related variation in TF release along ...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-128-4-1869
更新日期:1991-04-01 00:00:00
abstract::This study examined the effect of two thirds hepatectomy on rat liver insulin-like growth factor-II (IGF-II) receptors and IGF-II receptor messenger RNA (mRNA) levels. IGF-II receptor levels were determined in liver plasma membrane and Golgi/endosome fractions from sham-operated and hepatectomized rats by ligand bindi...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-127-5-2210
更新日期:1990-11-01 00:00:00
abstract::Arginine vasopressin (AVP) stimulates the secretion of ACTH from pituitary corticotropes. We investigated the action of AVP in single corticotropes of male rats. Corticotropes were identified with the reverse hemolytic plaque assay using antibodies against ACTH. Using the whole-cell recording technique in conjunction ...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.139.5.5999
更新日期:1998-05-01 00:00:00
abstract::Neonatal exposure to high doses of estrogen results in permanent suppression of prostate growth and reduced sensitivity to androgens in adulthood. It is unclear whether alterations in prostate growth are due to a direct effect of estrogens on the gland or are the result of hypothalamic-pituitary-gonadal axis suppressi...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.141.9.7648
更新日期:2000-09-01 00:00:00
abstract::Hyperaldosteronism is linked to the development and progression of several different cardiovascular diseases. Angiotensin (Ang) II increases aldosterone secretion and adrenal blood flow. Ang II peptide fragments are produced by various peptidases, and these Angs have diverse and vital physiologic roles. Due to the unc...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2013-1160
更新日期:2013-12-01 00:00:00
abstract::The distribution of peptide YY (PYY)-like immunoreactivity (IR) in rat tissues was determined by specific RIA after extraction with boiled 1 N acetic acid. The high concentration of PYY-IR was observed in the gastrointestinal tract, with concentrations gradually increasing from the duodenum to the end of colon. The co...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-118-6-2163
更新日期:1986-06-01 00:00:00
abstract::Endotoxin has been shown to stimulate GH secretion in human and sheep. However, changes in hypothalamic neurohormones involved in the GH regulation by endotoxin have never been studied in vivo. In sheep it is possible to collect hypophysial portal blood (HPB) and quantify GH-releasing hormone (GHRH) and somatostatin (...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.139.6.6072
更新日期:1998-06-01 00:00:00
abstract::In primary cultures of sheep pituitary cells extracellular nucleotides stimulated rapid increases in inositol tris- and bisphosphate, accompanied by intracellular Ca2+ mobilization. A similar stimulation of inositol phosphate production by extracellular nucleotides was observed in rat and baboon pituitary cells. The i...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-126-1-80
更新日期:1990-01-01 00:00:00
abstract::We have recently disclosed sustained episodes of LH release (minisurges) during the afternoons of the juvenile-peripubertal transition period in the female rat. To determine if these LH minisurges are gonad independent, i.e. develop in the absence of the ovaries, animals were ovariectomized when neonates, and the mode...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-118-3-1187
更新日期:1986-03-01 00:00:00
abstract::Specific binding of human chorionic gonadotropin (hCG), and the hCG-sensitive adenyl cyclase of granulosa cells from small (1-2 mm), medium (3-5 mm), and large (6-12 mm) porcine ovarian follicles have been studied. The number of hCG-binding sites per cell (n) increases during follicle maturation without a change in th...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-99-1-42
更新日期:1976-07-01 00:00:00
abstract::Pregnancy-associated plasma protein-A (PAPP-A) is the major IGF binding protein-4 (IGFBP-4) protease in follicular fluid, consistent with its proposed role in folliculogenesis. Despite growing interest, almost nothing is known about how PAPP-A expression is regulated in any tissue. Here we show that FSH and oocytes re...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2003-1642
更新日期:2004-08-01 00:00:00
abstract::The gene encoding the human TNF alpha receptor (TNFR) 2 contains polymorphisms in the 3' untranslated region (UTR). Previous studies have shown that some variant alleles in this region are associated with obesity and insulin resistance. However, the effect of these polymorphisms on the expression of TNFR2 has not been...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2004-1366
更新日期:2005-05-01 00:00:00
abstract::Food deprivation in laboratory rats induces profound changes in the neuroendocrine system. We have investigated the hypothalamic and pituitary responses of the hypothalamo-pituitary thyroid axis to 48-h food deprivation in Sprague-Dawley rats. Peripheral T3 and hypophysial portal TRH were measured by RIA, and TSH beta...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-129-5-2714
更新日期:1991-11-01 00:00:00
abstract::The injection of chlorpropamide into Brattleboro homozygous rats (di/di) has previously been shown to result in enhanced activation of renal medullary adenylate cyclase activity and increased renal medullary content of cAMP in response to 1-desamino-8-D-arginine vasopressin (dDAVP). In contrast, in vivo chlorpropamide...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-111-6-2025
更新日期:1982-12-01 00:00:00
abstract::Adipose tissue inflammation is associated with the development of insulin resistance. In obese adipose tissue, lipopolysaccharides (LPSs) and saturated fatty acids trigger inflammatory factors that mediate a paracrine loop between adipocytes and macrophages. However, the inflammatory signaling proteins underlying this...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2013-1815
更新日期:2014-03-01 00:00:00
abstract::Kisspeptin neurons play an essential role in the regulation of fertility through direct regulation of the GnRH neurons. However, the relative contributions of the two functionally distinct kisspeptin neuron subpopulations to this critical regulation are not fully understood. Here we analyzed the specific projection pa...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2015-1131
更新日期:2015-07-01 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::The aim of the present study was to investigate the presence and localization of the main G protein alpha-subunits in the human fetal adrenal gland during the second trimester of gestation. Immunofluorescence studies conducted on sections from frozen glands obtained immediately after therapeutic abortion indicated tha...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.141.12.7834
更新日期:2000-12-01 00:00:00