Abstract:
:In this study the hypothesis that the LHRH neurosecretory system of the prepubertal female monkey has the capacity to function in a manner comparable to that of monkeys in more mature stages of development was tested. Using push-pull perfusion in the stalk-median eminence, effects of electrical stimulation of the medial basal hypothalamus on in vivo LHRH release were determined in conscious prepubertal, early pubertal, and midpubertal monkeys. After a 180-min period of baseline sample collection, electrical stimulation was applied six times at 90-min intervals via a monopolar electrode, the tip of which was 1-2 mm rostro-dorsal to the perfusion site. Control experiments were performed in the same manner, but without electrical stimulation. During control perfusions, the mean LHRH level remained stable. Mean (+/- SEM) LHRH release for the entire perfusion period in control experiments was 0.5 +/- 0.2, 2.4 +/- 0.4, and 2.2 +/- 0.7 pg/ml.10 min for the prepubertal (n = 6), early pubertal (n = 4), and midpubertal (n = 6) groups, respectively. Mean LHRH release in the prepubertal group was significantly lower than that in either of the older groups (P less than 0.05). In contrast, in all three age groups, repeated electrical stimulation of the medial basal hypothalamus resulted in 1) a short latency increase in LHRH release occurring within 20 min after each stimulation, and/or 2) a gradual increase in mean LHRH release over several hours. In the prepubertal group (n = 4), mean LHRH levels were 0.8 +/- 0.5 pg/ml.10 min during the 90 min before the first electrical stimulation and increased to 6.1 +/- 2.9 pg/ml.10 min during the 90 min after the sixth stimulation. This degree of responsiveness was similar to that of the older age groups. Mean LHRH levels before stimulation were 1.3 +/- 0.6 and 2.4 +/- 1.1 pg/ml.10 min in the early pubertal (n = 5) and midpubertal (n = 5) groups, respectively, and increased to 7.8 +/- 3.5 and 6.0 +/- 1.8 pg/ml.10 min, respectively, after the sixth stimulation. These increases in LHRH concentration with electrical stimulation were significant for all three age groups (P less than 0.03-0.001), while there were no significant differences between age groups. The temporal patterns of these responses suggest that electrical stimulation elicits LHRH release with a similar magnitude in all three age groups by 1) depolarizing LHRH neurons directly, and/or 2) stimulating multineuronal systems that synapse with LHRH neurons.(ABSTRACT TRUNCATED AT 400 WORDS)
journal_name
Endocrinologyjournal_title
Endocrinologyauthors
Claypool LE,Watanabe G,Terasawa Edoi
10.1210/endo-127-6-3014subject
Has Abstractpub_date
1990-12-01 00:00:00pages
3014-22issue
6eissn
0013-7227issn
1945-7170journal_volume
127pub_type
杂志文章相关文献
ENDOCRINOLOGY文献大全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::Morphine sulfate was found to have a direct inhibitory effect on both basal and GnRH-stimulated LH release by cultured rat pituitary cells. The inhibitory effect of morphine on LH release was prevented by the opiate antagonist naltrexone, and treatment of cells with naltrexone or beta-endorphin antiserum significantly...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-118-5-2097
更新日期:1986-05-01 00:00:00
abstract::Lanosterol 14alpha-demethylase (CYP51) responds to cholesterol feedback regulation through sterol regulatory element binding proteins (SREBPs). The proximal promoter of CYP51 contains a conserved region with clustered regulatory elements: GC box, cAMP-response elements (CRE-like), and sterol regulatory element (SRE). ...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2005-0781
更新日期:2005-12-01 00:00:00
abstract::Hamsters injected sc with 50 mug estradiol cyclopentylpropionate (ECP) at 0900 h on day 1 (metestrus) of the cycle show the normal "postovulatory" vaginal discharge 4 days later but do not resume ovulation until 14--18 days later. After ECP injection ovarian histology reveals that the follicles normally destined to ov...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-97-4-878
更新日期:1975-10-01 00:00:00
abstract::Na(+)/I(-) symporter (NIS)-mediated iodide uptake into thyroid follicular cells serves as the basis of radioiodine therapy for thyroid cancer. NIS protein is also expressed in the majority of breast tumors, raising potential for radionuclide therapy of breast cancer. KT5823, a staurosporine-related protein kinase inhi...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2010-0782
更新日期:2011-03-01 00:00:00
abstract::Prepubertal reproductive development in juvenile male Siberian hamsters can be strongly influenced by photoperiod information received during gestation. Information transmitted from the mother hamster to her fetuses appears to modify the photoperiodic mechanism of the developing hamsters so that they may respond diffe...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.136.10.7664640
更新日期:1995-10-01 00:00:00
abstract::The proliferation and differentiation of testicular progenitor stem cells into highly specialized germ cells (spermatozoa) are largely controlled by the hormonally (FSH and testosterone) regulated adjacent supporting Sertoli cells. However, the factors involved in this control remain largely unknown. In the present st...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.141.8.7625
更新日期:2000-08-01 00:00:00
abstract::The purpose of these experiments was to test the hypothesis that estrogen has an anabolic effect on cancellous bone formation in long bones of growing rats. In the present studies, estrogen decreased measurements related to cancellous bone formation, including osteoblast number, fluorochrome-labeled bone perimeter, an...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.133.6.8243320
更新日期:1993-12-01 00:00:00
abstract::This paper describes experiments on cultured granulosa cells isolated from ovaries of immature rats designed to locate the site of action of androgens on FSH-induced aromatase activity. Treatment of cells during a 36-h induction period with (Bu)2cAMP, 8- BrcAMP , FSH, prostaglandin E2, or cholera toxin resulted in ind...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-114-6-1975
更新日期:1984-06-01 00:00:00
abstract::Both peroxisome proliferator-activated receptor-alpha (PPARalpha) and pancreatic/duodenal homeobox-1 (PDX-1) have been reported to be associated with glucose-stimulated insulin secretion (GSIS), but the relationship between PPARalpha and PDX-1 is not yet fully understood. In the present study, we tested the hypothesis...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2007-1275
更新日期:2008-02-01 00:00:00
abstract::The type 1 PTH/PTH-related peptide receptor (PTH1R) is a class B G protein-coupled receptor that demonstrates immunoreactivity in the nucleus as well as cytoplasm of target cells. Our previous studies on the PTH1R have shown that it associates with the importin family of transport regulatory proteins. To investigate t...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2007-0157
更新日期:2007-05-01 00:00:00
abstract::PRL gene expression in the anterior pituitary has been the focus of intensive investigation for many years, but very little information is available on the actual dynamics by which this process occurs in individual mammotrope cells. Here, we used single cell bioluminescent imaging microscopy and a recently refined rep...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.143.3.8682
更新日期:2002-03-01 00:00:00
abstract::Insulin-like growth factor (IGF)-binding protein-3 (IGFBP-3), the predominant IGF carrier protein in circulation, is posttranslationally modified in vivo by IGFBP-3 protease(s) into a number of fragments. Based on the ascertained and predicted recognition sites for known IGFBP-3 proteases, FLAG-epitope tagged intact I...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.141.11.7781
更新日期:2000-11-01 00:00:00
abstract::Stanniocalcin (STC) is a new mammalian polypeptide hormone and appears to be a regulator of neuronal function. We have already shown that the induction of STC mRNA and protein expression by cAMP is integral to neuroblastoma cell differentiation, particularly neurite outgrowth. In this study, we examined the cAMP pathw...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2003-0504
更新日期:2003-10-01 00:00:00
abstract::The adipokine leptin regulates energy homeostasis through ubiquitously expressed leptin receptors. Leptin has a number of major signaling targets in the brain, including cells of the anterior pituitary (AP). We have previously reported that mice lacking leptin receptors in AP somatotropes display growth hormone (GH) d...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endocr/bqaa245
更新日期:2021-03-01 00:00:00
abstract::PTH-related protein (PTHrP) has been shown to be a major factor responsible for hypercalcemia of malignancy. PTHrP acts via the PTH/PTHrP receptor, and therefore, PTH antagonists might be expected to reverse the hypercalcemia in malignancy. In the present studies, the PTH antagonists [Tyr34]bovine (b) PTH-(7-34)NH2, [...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.134.5.8156920
更新日期:1994-05-01 00:00:00
abstract::In contrast to other systems in which angiotensin-II (AII) inhibits adenylyl cyclase, in fetal skin fibroblasts the peptide stimulates cAMP accumulation. The mechanism of this novel effect was studied by analysis of the actions of AII and other regulators on the adenylyl cyclase system in cultured cells. In the presen...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.131.5.1330500
更新日期:1992-11-01 00:00:00
abstract::The metabolic consequences of visceral obesity have been associated with amplification of glucocorticoid action by 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) in adipose tissue. This study aimed to assess in a rat model of diet-induced obesity the effects of pharmacological 11beta-HSD1 inhibition on the m...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2006-1199
更新日期:2007-05-01 00:00:00
abstract::We have examined the regulation of an insulin-like growth factor-binding protein-3 (IGFBP-3) protease secreted by MCF-7 human breast cancer cells using a ligand-binding assay that relies on the decrease in affinity for des(1-3)IGF-I that occurs when IGFBP-3 becomes proteolyzed. IGFBP-3 protease activity was not altere...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.141.9.7684
更新日期:2000-09-01 00:00:00
abstract::Spontaneously hypertensive (SH) rats, extensively used as experimental models of essential human hypertension, display important alterations in the neuroendocrine reproductive axis, which manifest as markedly delayed puberty onset in females but whose basis remains largely unknown. We analyze herein in female SH rats:...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2008-1381
更新日期:2009-06-01 00:00:00
abstract::The distribution of androgen receptor expression within the developing rat gubernaculum was examined at different times during fetal and neonatal development using polyclonal antibodies directed at the amino-terminus (amino acids 1-21) and the carboxy-terminus (amino acids 898-917) of the androgen receptor. These stud...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-128-1-383
更新日期:1991-01-01 00:00:00
abstract::Immunohistochemical localization of androgen in the testes of both rat and squirrel monkey has been performed using an antiserum specific to testosterone and certain related androgens. The bound antibodies were visualized by coupling with antigammaglobulin labeled either with fluorescein isothiocyanate or with a horse...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-96-1-63
更新日期:1975-01-01 00:00:00
abstract::Molecular and cellular mechanisms involved in artificially induced ovarian differentiation were analyzed by exposing embryos of medaka (Oryzias latipes) to a potent nonsteroidal estrogen, diethylstilbestrol (DES). Embryos were exposed for short-exposure (SE) [from 0 to 8 d postfertilization (dpf)] and long-exposure (L...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2010-0812
更新日期:2011-02-01 00:00:00
abstract::Although leptin is a hormone mainly produced by the adipose tissue, it is also produced by the gastric mucosa and the mammary epithelium and is present in maternal milk. The effects of milk leptin on the neonate are not known. The purpose of the investigation was to evaluate the short-term effects of the administratio...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2005-0112
更新日期:2005-06-01 00:00:00
abstract::Isolated bone cells are often described according to the presence of PTH- and calcitonin (CT)-sensitive adenylate cyclase activities. Osteoblasts are thought to be cells with PTH-sensitive adenylate cyclase but without CT response, and osteoclasts are thought to be CT-sensitive cells. We have studied the adenylate cyc...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-115-6-2342
更新日期:1984-12-01 00:00:00
abstract::The preoptic area (POA) of the male dove is a known target area for separable behavioral actions of testosterone and 17 beta-estradiol (E2) and contains an active aromatase system. We have examined the regulatory influence of gonadal hormones on aromatase using an in vitro microassay that measures conversion of [1 alp...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-118-6-2180
更新日期:1986-06-01 00:00:00
abstract::The ability of different LH-like hormones, such as hCG, PMSG/equine (e) CG, ovine (o) LH, eLH, and rat (r) LH, to bind to and stimulate steroidogenesis in two types of rat gonadal cells was studied under the same experimental conditions. In both Leydig and granulosa cells, the maximal steroidogenic responses elicited ...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-116-2-597
更新日期:1985-02-01 00:00:00
abstract::Ghrelin is a peptide hormone primarily produced in the previously unidentified X/A endocrine cells of the stomach. Extensive studies have focused on the effects of ghrelin on growth hormone release and appetite regulation. However, the mechanisms regulating ghrelin secretion are less understood. In the present study, ...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2012-1040
更新日期:2012-08-01 00:00:00
abstract::Insulin resistance and type 2 diabetes mellitus are associated with impaired postprandial secretion of glucagon-like peptide-1 (GLP-1), a potent insulinotropic hormone. The direct effects of insulin and insulin resistance on the L cell are unknown. We therefore hypothesized that the L cell is responsive to insulin and...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2008-0726
更新日期:2009-02-01 00:00:00
abstract::Stress-responsive neurons of the hypothalamic paraventricular nucleus (PVN) show functional plasticity and adapt to repeated restraint (RR) stress. To investigate whether neuronal adaptation to the homotypic stress also affects their response to a heterotypic stressor, we used in situ hybridization with intronic and e...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.140.8.6943
更新日期:1999-08-01 00:00:00