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) within 30 min posttreatment; the effects of 0.02 nmol CRF lasted for at least 2 h, whereas those of 0.2 and 2 nmol CRF were evident for up to 6 h. Rats that received sc infusions of the opioid receptor antagonist naloxone (9.6 mg/kg.day) for 48 h before testing with 0.2 nmol CRF showed a significant reduction of the LH response to CRF. Rats that received two acute injections of naloxone (2 mg/kg, iv, 30 min apart) also showed an attenuated response to the LH-suppressive effects of CRF. In another experimental model where the opioidergic control of LH secretion is absent or masked, the long term castrate rat, there was also a marked attenuation of the LH-suppressing effects of CRF. Transient replacement of testosterone in long term castrates reinstated the inhibitory effects of CRF on LH secretion. A third experiment, in which short term castrates were pretreated with an opioid antibody and then with CRF, resulted in a significant reduction of the CRF-induced reduction of serum LH levels. These observations indicate that opioid receptor-mediated events play an important part in the actions of CRF on LH secretion. On the basis of our previous experiments in vitro, we propose that CRF stimulates the release of hypothalamic opioid peptides, which in turn inhibits the activity of LHRH neurons and, thus, LH secretion.
journal_name
Endocrinologyjournal_title
Endocrinologyauthors
Almeida OF,Nikolarakis KE,Herz Adoi
10.1210/endo-122-3-1034subject
Has Abstractpub_date
1988-03-01 00:00:00pages
1034-41issue
3eissn
0013-7227issn
1945-7170journal_volume
122pub_type
杂志文章相关文献
ENDOCRINOLOGY文献大全abstract::A 50-70% depletion in the anterior pituitary concentration of PRL occurred within 5 min of electrical stimulation of a single abdominal mammary nerve of urethane-anesthetized lactating rats previously nonsuckled for 6-8 h. The stimulus parameters were: 1-msec pulses, 10-20/sec at 5-30 V applied 5 sec on and 10 sec off...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-106-2-458
更新日期:1980-02-01 00:00:00
abstract::Whole saliva collected from rat, mouse, and human sources was found to contain high concentrations of transforming growth factor-alpha (TGF alpha) when analyzed by RIA. The concentrations of TGF alpha in unstimulated human saliva (age, 30-45 yr; n = 10; 1.5 +/- 3.1 nM) was reduced with age (age, 55-70 yr; n = 10; 0.4 ...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.134.2.8299590
更新日期:1994-02-01 00:00:00
abstract::Thyroid hormone action is mediated through its nuclear receptors (TRs), which bind to target DNA sequences [thyroid hormone response element (TRE)] as a homodimer or a heterodimer with 9-cis-retinoic acid receptors. Mutations of TR beta identified in patients with resistance to thyroid hormone (RTH) cluster primarily ...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.137.10.8828460
更新日期:1996-10-01 00:00:00
abstract::PTH-related peptide (PTHrP) has been shown to be the major mediator of hypercalcemia of malignancy, but may also exert effects on cell growth and differentiation. The Leydig cell tumor H-500, when implanted in Fischer rats, produces abundant PTHrP and eventually causes the death of the host animal. In the present stud...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.136.12.7588290
更新日期:1995-12-01 00:00:00
abstract::We investigated the effect of glucocorticoid on the generation of osteoclasts. In mouse bone marrow culture systems, dexamethasone, a synthetic glucocorticoid analog, enhanced osteoclast-like cell formation induced by 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] in a dose-dependent manner. Conversely, dexamethasone inhibit...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.134.3.8119150
更新日期:1994-03-01 00:00:00
abstract::Anandamide and 2-arachidonoylglycerol (2-AG), two endogenous ligands of the CB1 and CB2 cannabinoid receptor subtypes, inhibit the proliferation of PRL-responsive human breast cancer cells (HBCCs) through down-regulation of the long form of the PRL receptor (PRLr). Here we report that 1) anandamide and 2-AG inhibit th...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.141.1.7239
更新日期:2000-01-01 00:00:00
abstract::Cultured pineal ependymal cells from rat fetuses aged 17 to 19 days post-coitum release into their media a substance that has hydroosmotic, antidiuretic and rat uterine activities. Paper chromatography of concentrates from culture media demonstrates that the substance possessing all the above activities was eluted fro...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-100-1-205
更新日期:1977-01-01 00:00:00
abstract::Our previous studies implicated the involvement of protein kinase-A in the inhibitory effects of isoproterenol and relaxin on oxytocin-stimulated phosphoinositide turnover in rat myometrium. To understand the possible mechanisms involved, the properties and regulation of phospholipase-C (PLC) in purified myometrial pl...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.131.3.1324160
更新日期:1992-09-01 00:00:00
abstract::Contrary to widespread belief, the implantation of an embryo for the initiation of pregnancy is like a battle, in that the embryo uses a variety of coercive tactics to force its acceptance by the endometrium. We propose that embryo implantation involves a three-step process: (1) identification of a receptive endometri...
journal_title:Endocrinology
pub_type: 杂志文章,评审
doi:10.1210/en.2017-03082
更新日期:2018-02-01 00:00:00
abstract::Estrogens bind to two nuclear estrogen receptor (ER) subtypes, ERα and ERβ, which are expressed in differing amounts in various tissues. The endogenous estrogen, 17β-estradiol (E2), binds to both subtypes with nearly equal affinity and is the prototypical agonist. Selective estrogen receptor modulators (SERMs) may bin...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2018-00081
更新日期:2018-05-01 00:00:00
abstract::The hippocampus is essentially involved in learning and memory processes. Its functions are affected by various neuromodulators, including 17beta-estradiol, testosterone, and retinoid. Brain-synthesized steroid hormones act as autocrine and paracrine modulators. The regulatory mechanism underlying brain steroidogenesi...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2008-1644
更新日期:2009-09-01 00:00:00
abstract::The rate at which the estrogen receptor (ER) is synthesized and degraded (turns over) in target cells is a major factor regulating the levels of ER and cell sensitivity to estrogen. We have used the ability of tamoxifen aziridine [(TAZ)(Z)-1-[4-(2-[N-aziridinyl]ethoxy)phenyl]1,2-diphenyl-1-buten e] to affinity label t...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-119-5-2038
更新日期:1986-11-01 00:00:00
abstract::We examined the effects of ACTH and the Ca++ ionophore, A23187, on steroidogenesis and phospholipid metabolism during incubation of dispersed rat adrenal cells. Increasing doses of ACTH elicited nearly parallel increases in corticosterone production and adrenal inositide (mono- and di-) concentrations. As reported pre...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-108-4-1243
更新日期:1981-04-01 00:00:00
abstract::The effects of endothelin-1 (ET-1), a potent vasoconstrictor and mitogen to various cell types, on proliferation and differentiated functions of the murine Leydig tumor cell line MA-10 were investigated. Kinetic binding experiments at room temperature showed that [125I] ET-1 bound to MA-10 cells and reached equilibriu...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.132.2.8425480
更新日期:1993-02-01 00:00:00
abstract::Enlargement of the chimeric ventral prostate gland (VP) was induced by directly implanting either fetal urogenital sinus mesenchyme (UGM) or intact fetal urogenital sinus (UGS) into the VP of intact adult rats. The macromolecular content in the chimeric prostate increased from 40-100% (UGM implants) to 200-300% (UGS i...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-118-6-2437
更新日期:1986-06-01 00:00:00
abstract::We report here the desensitization and internalization of the relaxin receptor (RXFP1) after agonist activation in both primary human decidual cells and HEK293 cells stably transfected with RXFP1. The importance of beta-arrestin 2 in these processes has also been demonstrated. Thus, in HEK-RXFP1 cells the desensitizat...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2008-1385
更新日期:2009-05-01 00:00:00
abstract::The endocrine-disrupting chemical bisphenol A (BPA) increases adipose tissue mass in vivo and promotes adipogenesis in vitro; however, mechanisms explaining BPA's obesogenic effect remain unknown. We investigated the effects of gestational BPA and its analog, bisphenol S (BPS), exposure on the adipogenic differentiati...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2017-00615
更新日期:2017-11-01 00:00:00
abstract::The adipose conversion of 3T3-L1 fibroblasts depends on serum factors, one of which has been identified as GH. Human serum extracts obtained by heat treatment do not contain intact GH, as shown by RIA, but still support adipose conversion. After organic solvent extraction followed by reversed phase HPLC, two adipogeni...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-120-2-469
更新日期:1987-02-01 00:00:00
abstract::The adrenal zona glomerulosa (ZG) secretes aldosterone to regulate sodium balance. Chronic sodium restriction increases aldosterone accompanied by ZG expansion. The ZG is innervated by sympathetic, vasoactive intestinal polypeptide (VIP) and neuropeptide tyrosine (NPY), and sensory, calcitonin gene-related peptide, ne...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2010-0487
更新日期:2010-10-01 00:00:00
abstract::Endothelin (ET) and GnRH act through specific receptors to promote Ca2+ mobilization and influx pathways in pituitary gonadotrophs. In the present study cytoplasmic calcium ([Ca2+]i) and secretory responses to these two agonists are compared. In single gonadotrophs, low concentrations of both agonists cause oscillator...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.131.6.1446620
更新日期:1992-12-01 00:00:00
abstract::Evidence is presented that in vitamin D deficiency there are aberrations of estrogen metabolism in the laying hen. Five White Leghorn hens, 35 weeks of age, all laying soft shelled eggs as a result of complete withdrawal of supplemental vitamin D3 (D3) from the diet, were found to have a 3-fold higher molar ratio of p...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-115-6-2170
更新日期:1984-12-01 00:00:00
abstract::We studied the estrogen-dependent expression of epidermal growth factor (EGF), transforming growth factor (TGF) alpha, and EGF receptor gene transcripts in human fallopian tubes in vivo and in vitro. Competitive polymerase chain reaction (PCR) was performed on the fallopian tube RNA samples from the postmenopausal wom...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.136.5.7720660
更新日期:1995-05-01 00:00:00
abstract::To elucidate the mechanism of humoral hypercalcemia elicited by human esophageal carcinoma cells (EC-GI), which constitutively produced interleukin-1 alpha (IL-1 alpha) and PTH-like factor, the effects of IL-1 alpha and PTH-related protein (PTH-rP) on bone resorption in vitro and on serum calcium concentrations in viv...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-124-5-2172
更新日期:1989-05-01 00:00:00
abstract::Mesenchymal stroma/stem cells (MSCs) exist in adult tissues, such as adipose tissue and bone marrow, and differentiate into cells of multiple lineages. In previous studies, we found that MSCs differentiate into steroidogenic cells by forced expression of steroidogenic factor 1 (SF-1)/adrenal 4 binding protein (Ad4BP),...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endocr/bqaa007
更新日期:2020-03-01 00:00:00
abstract::3-Iodothyronamine (3-T 1 AM) and thyronamine (T AM) are novel endogenous signaling molecules that exhibit great structural similarity to thyroid hormones but apparently antagonize classical thyroid hormone (T(3)) actions. Their proposed biosynthesis from thyroid hormones would require decarboxylation and more or less ...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2007-1678
更新日期:2008-06-01 00:00:00
abstract::A midregion fragment of PTH-related protein (PTHrP), which is intensively conserved across species, has been identified as a secretory product of several different cell types, including keratinocytes and squamous carcinomas. As recent data suggest that a midregion PTHrP fragment may be biologically active, we hypothes...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.137.12.8940360
更新日期:1996-12-01 00:00:00
abstract::There are many precedents for the production from a single precursor of multiple peptides, with independent receptors and different bioactivities. Gastrin-releasing peptide (GRP) is initially synthesized as amino acids 1-27 of a 125-residue precursor, proGRP, and is subsequently cleaved and amidated to form GRP18-27. ...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2006-0466
更新日期:2007-03-01 00:00:00
abstract::It is believed that a combination of environmental factors with mutagens induces carcinomas derived from thyroid follicular cells. In this study we tried to ascertain whether a single short-term exposure to external radiation is sufficient to induce thyroid carcinomas in rats under long-term high or low dietary iodine...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.143.7.8914
更新日期:2002-07-01 00:00:00
abstract::Recently, we demonstrated that estradiol (E(2)) modulates cross-talk between protein tyrosine kinases and norepinephrine (NE) receptor signaling in the hypothalamus (HYP) and preoptic area (POA), brain areas that govern female reproductive function. We are now investigating the identity of protein tyrosine kinase(s) t...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.142.2.7946
更新日期:2001-02-01 00:00:00
abstract::TGF-β plays an important role in the progression of prostate cancer. It exhibits both tumor suppressor and tumor-promoting activities. Correlations between cyclooxygenase (COX)-2 overexpression and enhanced production of prostaglandin (PG)E2 have been implicated in cancer progression; however, there are no studies ind...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2012-2074
更新日期:2013-05-01 00:00:00