Abstract:
:The effect of aging on the release of gonadotropin-releasing hormone (GnRH) in vitro and of luteinizing hormone (LH) both in vivo and in vitro in ovariectomized (Ovx) rats was studied. Old (21-24 months) and young (3-4 months) rats were Ovx before use. They were injected subcutaneously with estradiol benzoate (25 micrograms/kg) or sesame oil for 3 days and then challenged with GnRH (0.5, 2 or 10 micrograms/kg) via a jugular catheter. Blood samples were collected immediately before and at 5, 10, 20, 40 and 60 min following GnRH injection. For in vitro study, Ovx rats were decapitated. The anterior pituitary glands (APs) were incubated with GnRH (0.1 or 10 nM) and estradiol (0, 0.1, 1 or 10 nM) at 37 degrees C for 30 min. The mediobasal hypothalamus was superfused with Locke's solution at 37 degrees C for 210 min, and stimulated with 60 mM KCl at 90 and 150 min. The medium samples were collected at 10-min intervals. Concentrations of GnRH and LH in plasma and medium samples were measured by radioimmunoassay. In all rats, the basal and GnRH-stimulated levels of plasma LH were lower in old than in young rats. The spontaneous release of LH in vitro from APs of Ovx rats was increased by aging, whereas GnRH-stimulated release of LH in vitro was lower in old than in young animals. The potassium-stimulated, but not spontaneous, release of GnRH was lower in old than in young Ovx rats.(ABSTRACT TRUNCATED AT 250 WORDS)
journal_name
Neuroendocrinologyjournal_title
Neuroendocrinologyauthors
Hwang C,Pu HF,Hwang CY,Liu JY,Yao HC,Tung YF,Wang PSdoi
10.1159/000125562subject
Has Abstractpub_date
1990-08-01 00:00:00pages
127-32issue
2eissn
0028-3835issn
1423-0194journal_volume
52pub_type
杂志文章abstract::The timing of the episodic secretion of luteinizing hormone (LH) in ovariectomized ewes was investigated with respect to an ultradian rest-activity cycle. Individual sheep were enclosed in a chamber where their physical activity was continuously monitored, and blood samples for LH analysis were collected at 5-min inte...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123187
更新日期:1981-06-01 00:00:00
abstract::The sheep exhibits a marked sex difference in the timing of the pubertal increase in luteinizing hormone (LH). Male lambs undergo a reduction in sensitivity to inhibitory steroid feedback, leading to an increase in LH by 10 weeks of age, but females remain hypersensitive until 30 weeks of age. Endogenous opioids suppr...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126312
更新日期:1992-12-01 00:00:00
abstract::Pituitary transcription factor-1 (Pit-1 or GHF-1) is a transcription factor specific to the anterior pituitary and is involved in the expression and regulation of the growth hormone (GH), prolactin (PRL) and thyroid-stimulating hormone (TSH) beta-subunit genes. The expression of these three genes can be modulated by c...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126930
更新日期:1996-01-01 00:00:00
abstract::Leptin exerts important effects on the regulation of food intake and energy expenditure by acting in the brain. Leptin action is mediated by the interaction with a receptor that is alternatively spliced, resulting in at least five different isoforms. The long form (OB-Rb) has a long intracellular domain that is essent...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000054536
更新日期:2000-03-01 00:00:00
abstract::Gastroenteropancreatic (GEP) neuroendocrine neoplasms (NEN) are a rare, heterogeneous group of tumors that originate from the endocrine system of the gastrointestinal tract and pancreas. GEP-NEN are subdivided according to their differentiation into well differentiated gastroenteropancreatic neuroendocrine tumors (NET...
journal_title:Neuroendocrinology
pub_type: 杂志文章,评审
doi:10.1159/000509864
更新日期:2020-07-02 00:00:00
abstract::The c-fos protein is rapidly induced in hypothalamic magnocellular nuclei following hemorrhage. We used specific antibodies directed against c-fos and either vasopressin (AVP) or oxytocin (OT) neurophysin to investigate c-fos activation in individual AVP and OT neurons. AVP and OT neurons expressed c-fos in response t...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126384
更新日期:1993-03-01 00:00:00
abstract::The expression of the mouse metallothionein-I (mMT) promoter/human growth hormone (hGH) fusion gene in transgenic mice leads to female sterility and major alterations in the function of the hypothalamic-adenohypophyseal system. These alterations include increases in median-eminence norepinephrine turnover and plasma L...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125743
更新日期:1991-04-01 00:00:00
abstract::Knowledge of specific neurotransmitters as well as the pathways and mechanisms regulating appetite in ruminants that continually graze, such as sheep, is incomplete. Although fundamentally agouti-related protein (AGRP) has a similar function across species to increase food intake, the regulation of AGRP may vary acros...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000082735
更新日期:2004-01-01 00:00:00
abstract::We have examined the effect of electrical stimulation in the subfornical organ (SFO) on the activity of neurons in the medial septum and diagonal band of Broca (MS-DBB) which project to the median eminence in the rat. Previous studies have suggested that septal neurons with such projections are luteinizing hormone rel...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124991
更新日期:1988-07-01 00:00:00
abstract::Pregnant rats were kept on an ethanol-containing (6% w/v) liquid diet from the 13th day of gestation and serum growth hormone (GH) levels were determined in the offspring after four different experimental paradigms. In controls, administration of cyproheptadine (a serotonin-blocking agent), or insulin, or exposure to ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123910
更新日期:1984-04-01 00:00:00
abstract::Physiological brain aging is characterized by important biochemical and structural changes and by the unbalance among the different neurotransmitters and neuromodulators. The study of the circadian organization of neuroendocrine functions may be considered a clinically reliable tool to investigate the changes of the C...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126869
更新日期:1995-04-01 00:00:00
abstract::The present studies were undertaken to investigate the effect of gender on thyrotropin-releasing hormone (TRH) gene expression in cultured anterior pituitary (AP) cells. AP cells derived from 15-day-old male, female, or female pups that had been neonatally treated with testosterone propionate (TP), were cultured for u...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126815
更新日期:1995-01-01 00:00:00
abstract::The effects of the dopamine (DA) receptor antagonist metoclopramide on the plasma thyroid stimulating hormone (TSH) and prolactin (PRL) levels were studied in 8 patients with subclinical hypothyroidism (defined as absence of clinical signs of hypothyroidism with normal thyroid hormone levels, normal or slightly increa...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124603
更新日期:1986-01-01 00:00:00
abstract::Corticosterone (CORT) can alter several electrophysiological properties in the hippocampus. Few studies have reported the effects of CORT on hippocampal long-term potentiation (LTP). In the CA1 region of the hippocampal slice, we studied the relative increase in population spike (PS) amplitude after inducing tetanus (...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126717
更新日期:1994-07-01 00:00:00
abstract::Glucocorticoid hormones have important effects on brain function in the context of acute and chronic stress. Many of these are mediated by the glucocorticoid receptor (GR). GR has transcriptional activity which is highly context-specific and differs between tissues and even between cell types. The outcome of GR-mediat...
journal_title:Neuroendocrinology
pub_type: 杂志文章,评审
doi:10.1159/000499659
更新日期:2019-01-01 00:00:00
abstract::The expression of the alpha-subunit of the glycoprotein hormones was studied in the developing rat pituitary by in situ hybridization and immunocytochemical techniques. The alpha-subunit mRNA labelling was detected in Rathke's pouch at 12 days' gestation (E12); at E13, it was exclusively concentrated in the pars tuber...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126600
更新日期:1993-12-01 00:00:00
abstract::A significant increase of cell multiplication in inoculated ascitic and solid tumors was demonstrated in both DBA/2 and C57BL/6 mice as well as in Wistar rats after radiofrequency lesions in the median hypothalamus (ventromedial and dorsomedial nuclei; part of arcuate nucleus). The following tests were performed: mito...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124479
更新日期:1986-01-01 00:00:00
abstract::Vasopressin-containing neurosecretory cells are partly regulated by GABAergic neurons present both at the hypothalamic and the pituitary level. In the present work, we compared GABA effects on vasopressin release from posterior pituitaries of Sprague-Dawley (SPD), Wistar (W), Wistar-Kyoto (WKY) and spontaneously hyper...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126585
更新日期:1993-11-01 00:00:00
abstract::The relationship between the growth hormone/insulin-like growth factor (GH-IGF)-I status and memory performance is studied in 24 elderly males and females, aged 75-85 years. Positron emission tomography (PET) was used to measure differences in regional cerebral blood flow during the performance of a delayed-non-match-...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000084872
更新日期:2005-01-01 00:00:00
abstract::Bromocriptine or other dopamine agonists are usually effective for the treatment of prolactin-secreting adenomas. Five to 18% of prolactinomas, however, do not respond to such therapy. We have shown previously that such resistance to bromocriptine correlates with reduced binding to the D2 receptor subtype of dopamine,...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126764
更新日期:1994-09-01 00:00:00
abstract::Vasoactive intestinal peptide (VIP), a prolactin (PRL)-releasing factor, has been shown to be synthesized within the anterior pituitary. To test the hypothesis that estrogens increase PRL secretion, at least in part, by stimulating VIP secretion, the concentrations of VIP, peptide histidine isoleucine (PHI) and prepro...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125622
更新日期:1990-11-01 00:00:00
abstract::The postnatal development of the luteinizing hormone-releasing hormone (LHRH) system in male and female rats was investigated using light microscopic immunocytochemistry. An identical number of immunoreactive LHRH cells (about 1,300) was observed for males and females throughout development. Two LHRH cell types, based...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124516
更新日期:1986-01-01 00:00:00
abstract::There is a great deal of conflicting data regarding the issue of whether androgens influence opiate receptors in the whole male rat brain. Although Hahn and Fishman initially reported that long-term castration produced a large increase in the density of opiate-binding sites, relative to controls, no other independent ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124816
更新日期:1987-08-01 00:00:00
abstract:BACKGROUND/AIM:Somatostatin (SST) analogs are mainstay for controlling tumor proliferation and hormone secretion in carcinoid patients. Recent data suggest that extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation may potentiate the anti-tumor effects of SST analogs in carcinoids. Additionally, ERK1/2 pho...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000341810
更新日期:2013-01-01 00:00:00
abstract::Brain sexual differentiation is mediated through testosterone, which acts during the perinatal period in the form of both 5alpha-dihydrotestosterone and estradiol. In order to gain insight into the molecular mechanisms involved, we studied induction of c-fos, an index of functional neuronal activation, in the 2-day-ol...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000054657
更新日期:2001-06-01 00:00:00
abstract::Pit-1 expression has been reported to be cell-type-specific in the adult human pituitary and in human pituitary adenomas. In contrast, studies of rodent fetal adenohypophysial development as well as mature rodent glands have indicated that the pit-1 mRNA is ubiquitously expressed and the protein is under translational...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126975
更新日期:1996-04-01 00:00:00
abstract::Immunoreactive thyroid-stimulating hormone (IR-TSH) has been detected in the hypothalamus and is released in vitro by a calcium-dependent mechanism when the tissue is depolarized. Recently, immunocytochemical studies have revealed that IR-TSH is present in thyrotropes in the pars tuberalis. Therefore, because these th...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124149
更新日期:1985-07-01 00:00:00
abstract::After the combined treatment with dexamethasone, morphine and pentobarbitone, the electrical stimulation in the rat tuber cinereum induces a rise in plasma corticosterone (CS) level, probably by direct stimulation of the corticoliberin-producing neural elements and the consecutive ACTH release. We have attempted to lo...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000122803
更新日期:1978-01-01 00:00:00
abstract::Thyroid hormones and nitric oxide/cyclic guanosine monophosphate (NO/cGMP) signaling play a significant role in the structural development of the cerebellum, respectively. In the present study, the possible contribution of neuronal NO synthase (NOS) and cGMP in the thyroid hormone-induced structural changes was invest...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000203644
更新日期:2009-01-01 00:00:00
abstract::Gonadal steroids exert an important regulatory influence upon the biosynthetic and secretory activity of the somatostatin and growth hormone-releasing hormone (GHRH) neurons controlling the release of growth hormone. It is hypothesized that some of these effects occur in an indirect transsynaptic manner through the st...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000064428
更新日期:2002-08-01 00:00:00