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 suppress LH secretion in the female lamb prepubertally and in adult male and female sheep. It has been suggested that a reduction in opioid inhibition of LH secretion is the signal to time puberty. Therefore, if a decrease in opioid tone occurs during sexual maturation, it should begin earlier in the male lamb than in the female. The objective of this study was to compare opioid inhibition of LH secretion in male and female lambs in relation to the timing of puberty. Our approach was to examine the response to the opioid antagonist naloxone at various ages in both sexes. To determine the timing of the pubertal LH rise in the presence of constant inhibitory steroid feedback, male and female lambs (n = 5 each) were gonadectomized at 3 weeks of age and implanted with a Silastic capsule of estradiol. They were then challenged with naloxone at 5, 11, and 23 weeks of age; blood samples were collected every 12 min for 8 hours, and lambs received naloxone (1 mg/kg i.v.) at hours 4, 5, 6, and 7. Mean LH before and during naloxone treatment was compared at each age.(ABSTRACT TRUNCATED AT 250 WORDS)
journal_name
Neuroendocrinologyjournal_title
Neuroendocrinologyauthors
Wood RI,I'Anson H,Ebling FJ,Foster DLdoi
10.1159/000126312subject
Has Abstractpub_date
1992-12-01 00:00:00pages
822-30issue
6eissn
0028-3835issn
1423-0194journal_volume
56pub_type
杂志文章abstract::In vivo single-unit extracellular recording was used to assess neuronal membrane sensitivity at the level of the midbrain central gray (MCG) to the iontophoresis of luteinizing hormone releasing hormone (LHRH) and beta-endorphin (beta-END). The percentage of change in firing rate was evaluated to determine the effect ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124792
更新日期:1987-06-01 00:00:00
abstract::The hypothalamic preoptic area (POA) was electrically stimulated through permanently implanted electrodes in 4 unanesthetized sheep. Initiation of POA stimulation was followed witin 10-20 min by large increases in plasma levels of prolactin (PRL). The stimulation-induced discharges of PRL were consistently observed in...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000122384
更新日期:1975-01-01 00:00:00
abstract::In the Djungarian hamster Phodopus sungorus, the daily temporal pattern of synthesis and release of pineal hormone melatonin, mainly the length of the period of elevated melatonin levels, may be involved in transferring the information on day length to the neuroendocrine-gonadal axis. The present study investigated th...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123895
更新日期:1984-03-01 00:00:00
abstract::Neuronal nitric oxide synthase, e.g. NADPH diaphorase (NADPH-d), catalyzes formation of the free radical, nitric oxide (NO), and occurs within brain structures that have functional significance for energy fuel homeostasis. The following studies examined whether populations of NADPH-d-positive neurons in the hypothalam...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000054417
更新日期:1999-03-01 00:00:00
abstract:OBJECTIVE:Differences in the cardiovascular and hypothalamic-pituitary-adrenal (HPA) axis functions at high altitudes (HAs) between visitors to and natives of HA were examined. METHODS:The cardiovascular functions and peripheral oxygen saturation (SPO2) were monitored, and the cortisol awakening response (CAR) and nig...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000363367
更新日期:2014-01-01 00:00:00
abstract::We studied the effects of selected leukotrienes and hydroxyeicosatetraenoic acids (HETEs) on prolactin release from primary cultures of female rats anterior pituitary cells. Leukotrienes B4, C4, and D4 had no effect on basal prolactin release; however, they did enhance prolactin release that was stimulated by 1 or 5 n...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125042
更新日期:1988-10-01 00:00:00
abstract::[125I]-neuropeptide Y receptors were characterized in the rat pituitary gland using quantitative autoradiography. Scatchard analysis of saturation isotherms showed high affinity (Kd 8.5 x 10(-11) M) and single class of binding sites (Bmax 0.22 pmol/mg of protein) in the posterior lobe of the pituitary gland, with no s...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125608
更新日期:1990-10-01 00:00:00
abstract::Molecules of astrocyte origin influence gonadotropin-releasing hormone (GnRH) release and GnRH neuronal growth and differentiation. Furthermore, type 1 astrocytes express steroid receptors, presenting the possibility that steroid actions on GnRH neurons might occur via astrocytes. Utilizing GT1-7 cells, a GnRH-secreti...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000059434
更新日期:2002-06-01 00:00:00
abstract::The pineal gland in the rat exhibits a diurnal rhythm in activity of the enzyme serotonin N-acetyltransferase (N-AT) with peak values during the dark period of a diurnal lighting schedule approximately 100-fold those during the light period. After blinding the rhythm becomes free-running. It is abolished by partial hy...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000122489
更新日期:1976-01-01 00:00:00
abstract:BACKGROUND:Kisspeptins are recognized as important stimulators of gonadotropin-releasing hormone (GnRH) and gonadotropin secretion. In sheep, the nonbreeding (anestrous) period is characterized by reduced Kiss1 mRNA expression in the hypothalamus. The aim of the present study was to determine whether the response to ki...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000227806
更新日期:2009-01-01 00:00:00
abstract::The hypophysial portal vessels and anterior pituitary glands of adult male rats were surgically exposed, cannulated and infused for 1 min with saline, growth hormone-releasing factor (GH-RF), and dbcAMP. After cessation of infusion, anterior pituitary glands were collected at 1, 5, 15, 30 or 60 min for electron micros...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000122421
更新日期:1975-01-01 00:00:00
abstract::Estrogens are crucial determinants in the regulation of anterior pituitary function and maintenance of tissue homeostasis. Estrogen actions in this gland are exerted through both classical and non-classical mechanisms of action. This review summarizes the expression of classical α- and β-estrogen receptors and variant...
journal_title:Neuroendocrinology
pub_type: 杂志文章,评审
doi:10.1159/000321683
更新日期:2010-01-01 00:00:00
abstract::The effect of intravertebral infusion of angiotensin II on cardiac vagal efferent activity was studied in anesthetized mongrel dogs. Unilateral infusion of doses of angiotensin II as low as 5 ng/kg/min inhibited basal vagal tone and also decreased the slope of the relationship between cardiac vagal efferent activity a...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124120
更新日期:1985-06-01 00:00:00
abstract::Although glutamate is the predominant excitatory amino acid in the vertebrate central nervous system (CNS) where it affects a variety of physiological processes and pathophysiological states, the role that glutamate receptors may play outside the CNS has not been clearly established. In the present study, the effects ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126995
更新日期:1995-08-01 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::Circadian rhythms occur in hypothalamic serotonin content in the turkey. Inhibition of serotonin (5-HT) synthesis by parachlorophenylalanine (PCPA) blocks circadian variation in hypothalamic serotonin levels suggesting that the major cause of diurnal fluctuations is differing rates of synthesis of the amine. PCPA trea...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123299
更新日期:1982-03-01 00:00:00
abstract::A number of neurochemical messengers have been shown to act directly on the melanotrope cells of the pars intermedia of Xenopus laevis to regulate alpha MSH secretion. In the present study the possibility that the melanotropes are also indirectly controlled has been examined. For this purpose, the characteristics of a...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125853
更新日期:1991-07-01 00:00:00
abstract::Previous work has demonstrated that N-methyl-D-aspartate (NMDA) is capable of stimulating luteinizing hormone release in a variety of species. Interestingly, the ability of NMDA to stimulate luteinizing hormone release is significantly compromised in castrated male and female rats as compared to intact animals. The pu...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126607
更新日期:1993-12-01 00:00:00
abstract::Using two tests in intact adult rats, it has been found that a high positive correlation exists (p less than 0.005) between the ovulation inhibiting and the serotonin antagonistic activities measured in vivo of five tricyclic compounds and ten ergot derivatives. In these chemically different classes of compounds, cert...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123005
更新日期:1980-04-01 00:00:00
abstract::Gastroenteropancreatic (GEP) endocrine tumors are hypervascular tumors able to synthesize and secrete high amounts of VEGF. We aimed to study the regulation of VEGF production in GEP endocrine tumors and to test whether some of the drugs currently used in their treatment, such as somatostatin analogues and mTOR inhibi...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000289569
更新日期:2010-01-01 00:00:00
abstract::The effects of GABAa receptor activation on the secretion of alpha-melanocyte-stimulating hormone (alpha-MSH) from the superfused pars intermedia of the amphibian Xenopus laevis were examined. The GABAa receptor agonist isoguvacine inhibited secretion of alpha-MSH from the pars intermedia, an action completely antagon...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126516
更新日期:1993-07-01 00:00:00
abstract::Interactions between the hypothalamic-pituitary-adrenocortical (HPA) system and melatonin secretion have been demonstrated, but only the effects of melatonin on the activity of the HPA system have been studied in man. Alterations of melatonin secretion described as low-melatonin syndrome have been demonstrated in pati...
journal_title:Neuroendocrinology
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1159/000127186
更新日期:1997-04-01 00:00:00
abstract::Prolactin (PRL) secretion in the female rat is regulated by an endogenous stimulatory rhythm (ESR), which is normally under the tonic inhibition of dopamine (DA). The ESR consists of a nocturnal (N) component which peaks at approximately 03.00 h, and a diurnal (D) component which peaks at approximately 17.00 h. This E...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125694
更新日期:1991-01-01 00:00:00
abstract::The effect of in vivo corticosterone manipulation on binding sites for the excitatory neurotransmitter glutamate was determined using radioligand binding to rat brain cryostat sections and crude synaptic membranes. 3H-glutamate binding to regions of the dorsal hippocampal formation was significantly decreased in adren...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125017
更新日期:1988-09-01 00:00:00
abstract::In previous studies we obtained evidence that serotonin release by p-chloroamphetamine (PCA) causes an increase in corticosterone secretion but that this effect is not mediated via the raphe nuclei in the midbrain. In contrast, PCA-induced prolactin secretion was abolished by dorsal raphe lesions. In the present study...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124205
更新日期:1985-11-01 00:00:00
abstract::The role of endogenous opiate peptides in the mesencephalic central gray (MCG) and their possible interactions with gonadotropin-releasing hormone (GnRH) in the regulation of lordosis behavior was assessed in ovariectomized, estrogen-treated and estrogen-progesterone-treated female rats. Lordosis behavior triggered by...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123983
更新日期:1984-09-01 00:00:00
abstract:BACKGROUND:Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) express insulin-like growth factor (IGF)-related factors [IGF1, IGF2; insulin receptor (IR)-A, IR-B; IGF-binding protein (IGFBP) 1-3] as well as somatostatin (SSTRs) and dopamine D2 receptors (D2Rs). OBJECTIVES:To (1) compare mRNA expression of IGF-rel...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000444280
更新日期:2016-01-01 00:00:00
abstract::Lewis (LEW) and Fischer 344 (F344) rats differ in responsiveness of the hypothalamo-pituitary-adrenocortical (HPA) axis as well as in their behavioral responses to drugs of abuse. The present experiments were conducted to compare hypothalamic corticotropin-releasing factor (CRF), plasma adrenocorticotropic hormone (AC...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126940
更新日期:1996-01-01 00:00:00
abstract::Introduction Autophagic cell death in cancer cells can be mediated by inhibition of deacetylases. Although extensive studies have focused on the autophagic process in cancer, little is known about the role of autophagy in degrading cytosolic and nuclear components of pancreatic neuroendocrine neoplastic (pNEN) cells l...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000512567
更新日期:2020-10-27 00:00:00
abstract::The polyphenol curcumin (diferuloylmethane) is the active componenet of the spice plant Curcuma longa and has been shown to exert multiple actions on mammalian cells. We have studied its effect on folliculostellate (FS) TtT/GF mouse pituitary cells, representative of a multifunctional, endocrine inactive cell type of ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000287236
更新日期:2010-01-01 00:00:00