Abstract:
:The frequency of pulsatile release of gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) is high in the breeding season and low in the nonbreeding season. These alterations in the patterns of GnRH and LH release are due to an interaction of daylength and gonadal steroid negative feedback. A vast amount of data indicates that steroid-responsive neural systems may play a role in regulating seasonal changes in GnRH release. One candidate system is neuropeptide Y (NPY). To determine the independent and interactive influences of photoperiod and steroid exposure on NPY mRNA levels, we used hypothalamic tissue from four groups (n = 4 per group) of castrated male sheep that were simultaneously housed in photochambers and exposed to: (1) a 16L:8D photoperiod (LD); (2) LD and implanted with testosterone (LD + T); (3) a 10L:14D photoperiod (SD), and (4) SD + T. Circulating levels of T averaged 2.8 +/- 0.2 ng/ml in implanted animals, but were undetectable in nonimplanted males. Mean LH levels were significantly reduced (p < 0.01) in the LD + T group as compared with the other groups which did not differ from each other. The silver grain area per NPY neuron in the arcuate nucleus, as assessed by in situ hybridization, was inversely related to mean LH values, with the grain area per cell being significantly greater (p < 0.05) for LD + T males than for all other groups which did not differ from each other. NPY cell numbers were not significantly different (p > 0.10) among the treatment groups. These results show that NPY mRNA expression is increased in male sheep during a LD photoperiod in a T-dependent manner. Our data are consistent with the idea that NPY is involved in the seasonal regulation of GnRH and LH release in the male sheep.
journal_name
Neuroendocrinologyjournal_title
Neuroendocrinologyauthors
Dobbins A,Lubbers LS,Jackson GL,Kuehl DE,Hileman SMdoi
10.1159/000076631subject
Has Abstractpub_date
2004-02-01 00:00:00pages
82-9issue
2eissn
0028-3835issn
1423-0194pii
76631journal_volume
79pub_type
杂志文章abstract::This study was designed to investigate the effects of penfluridol, a potent neuroleptic calmodulin inhibitor, on basal and secretagogue-stimulated secretion of thyroid-stimulating hormone (TSH), growth hormone (GH), and luteinizing hormone (LH). The drug had no effect on basal TSH or LH release, but decreased GH relea...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123548
更新日期:1983-09-01 00:00:00
abstract::Immobilization of adult male rats resulted in concomitant, significant releases of prolactin (PRL) and oxytocin (OT). Naloxone (0.2 mg/kg, i.p.) administration 30 min prior to initiation of restraint resulted in a significant diminution of the PRL response to stress. On the other hand, a significant augmentation of OT...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124053
更新日期:1985-01-01 00:00:00
abstract::The present study investigates the role of melanotrope proopiomelanocortin-derived peptide in the interrenal stress response to different stressors in male gilthead sea bream, Sparus aurata. Plasma cortisol and acetyl salmon endorphin (acetyl s-EP), as well as pituitary acetyl s-EP contents, were measured during two s...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000054359
更新日期:1998-08-01 00:00:00
abstract::Estrogen increases methamphetamine (MA)-induced neurotoxicity within the impaired nigrostriatal dopaminergic (NSDA) system of ovariectomized female mice, as defined by enhanced striatal dopamine (DA) depletion. In this study we compared the effects of a lower dose of estradiol benzoate (EB, 1 microg) with related agen...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000095338
更新日期:2006-01-01 00:00:00
abstract::Accumulating evidence in rodents suggests that a prolactin locally synthesized and released within the brain can act together with that taken up from the circulation to modulate neuroendocrine responses. The present study was designed to identify the regional patterns of prolactin expression in the adult and developin...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000114643
更新日期:2008-01-01 00:00:00
abstract:AIM:To extensively explore microRNA expression profiles in lung carcinoids in correlation with clinical and pathological features. METHODS:A PCR-based array was employed in the screening phase to analyze 752 microRNAs in a discovery set of 12 lung carcinoids, including 6 typical (3 with lymph node metastasis) and 6 at...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000381454
更新日期:2015-01-01 00:00:00
abstract::The present study provides evidence of a novel neuronal pathway for the control of GnRH secretion involving bradykinin neurons. Bradykinin neurons were shown by immunohistochemistry to be densely localized in several regions of the brain including the cortex, hippocampus and supraoptic nucleus, as well as two regions ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000054316
更新日期:1998-04-01 00:00:00
abstract::The effect of frontal deafferentation of the medial basal hypothalamus on pro-opiomelanocortin (POMC) gene expression was studied in the intermediate lobe (IL) and anterior lobe (AL) of the pituitary gland in the absence and presence of corticosterone (CORT). The lesion in the basal hypothalamus removed neural inputs ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124936
更新日期:1988-04-01 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::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::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::Dopaminergic agonists are effective in vivo in inhibiting lactotrope proliferation and prolactin (PRL)-secreting pituitary tumors. The purpose of the present study was to demonstrate in vitro actions of dopaminergic agents on proliferation and cell shape of rat lactotropes. Anterior pituitary cells cultured with serum...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000054362
更新日期:1998-09-01 00:00:00
abstract::Light deprivation by blinding or exposure to short photoperiod results in depressed prolactin (PRL) cell activity and gonadal regression in the male Syrian hamster after at least 42-56 days of treatment, and both of these events can be prevented if pineal removal accompanies light deprivation. In the present study, we...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125272
更新日期:1989-11-01 00:00:00
abstract::Acetylcholinesterase (AChE) activity, and concentrations of monoamines, monoamine metabolites and oxytocin (OT) were measured in the cerebrospinal fluid (CSF) of sheep during late pregnancy, labour, parturition, vaginocervical stimulation, lamb separation and suckling. Concentrations of AChE, 4-hydroxy-3 methoxyphenyl...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124638
更新日期:1986-01-01 00:00:00
abstract::The involvement of histaminergic transmission in the rapid and sustained plasma ACTH and corticosterone (CORT) responses induced in conscious rats by intra-arterial infusions of 25 micrograms.kg-1 Escherichia coli lipopolysaccharide (LPS) was investigated. LPS challenge produced a rapid and transient increase (+ 62%) ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126961
更新日期:1996-03-01 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::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::Infusion of the three human prepro-VIP derived peptides [vasoactive intestinal peptide (VIP), peptide histidine methionine (PHM) and the newly discovered peptide histidine valine (PHV-42)] at a constant nominal rate of 5 pmol/kg/min in 6 healthy volunteers for 60 min resulted in plateau plasma levels of 56,475 and 1,0...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125071
更新日期:1988-12-01 00:00:00
abstract::To characterize the short-term ACTH secretion pattern and to investigate factors regulating it, pituitary venous (PV) blood was collected using our nonsurgical method from 8 unperturbed horses every 20 or 30 s for approximately 1 h. In all but 1 horse, sampling occurred during the broad circadian maximum in plasma cor...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126755
更新日期:1994-09-01 00:00:00
abstract::At present there is no clinical guideline or standardised protocol for the treatment of metastatic or invasive phaeochromocytoma and paraganglioma (collectively known as PPGL) due to the rarity of the disease and the lack of prospective studies or extended national databases. Prognosis is mainly determined by genetic ...
journal_title:Neuroendocrinology
pub_type: 杂志文章,评审
doi:10.1159/000499497
更新日期:2019-01-01 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::In order to evaluate the possible participation of the hypothalamic excitatory and inhibitory amino acid neurotransmitter systems in the GnRH release response to GABAergic drugs, hypothalami (preoptic and mediobasal area) of immature (26 days of age) and adult male rats were perifused with GABA-A and -B agonists and a...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000127133
更新日期:1996-10-01 00:00:00
abstract::The present study was undertaken in order to better characterize the functional state of anterior pituitary gland in young and old rats by using prolactin secretion and incorporation of radioactive phosphate into phosphatidylinositol (PI) as markers. The in vitro incorporation of radiolabeled phosphate into anterior p...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124714
更新日期:1987-02-01 00:00:00
abstract::Normal and castrated male rats implanted with permanent right atrial cannulae were used, and sequential blood samples were taken every 2 min through the cannula. When the rats, both normal and castrated, were exposed to ether for 2 min, the prolactin (Prl) concentration in plasma was immediately and dramatically eleva...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000122826
更新日期:1978-01-01 00:00:00
abstract::Allopregnanolone is a neuroactive steroid synthesized in rat gonads, adrenal cortex, and central nervous system. It has been suggested that sex steroid hormones might influence allopregnanolone concentrations but no clear data have ever been reported. The aim of the present study was to investigate the effects of admi...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000054583
更新日期:2000-09-01 00:00:00
abstract::In these three experiments, we investigated the effect of adrenalectomy and adrenal demedullation on the stress-induced impairment of long-term potentiation (LTP) in the rat hippocampal slice. In the first, adrenalectomy alone resulted in a significant reduction in LTP, while exposure to stress resulted in a further r...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125318
更新日期:1990-01-01 00:00:00
abstract::The potential involvement of the sympathoadrenal system in stress-induced secretion of peptides from the intermediate lobe of the pituitary gland and the activation of the pituitary-adrenal axis was studied. Male Wistar rats were subjected to control procedures, to sympathectomy by chronic administration (8 weeks) of ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124746
更新日期:1987-04-01 00:00:00
abstract::Neonatal rats exhibit a period of diminished pituitary and adrenocortical responses to stress during the first 2 weeks of life. Since thyroid hormones are known to affect brain development, modulation of these responses to stress by alterations in thyroid hormone status have been investigated in hypothyroid (Hypo) and...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125232
更新日期:1989-09-01 00:00:00
abstract::Prolactin release from primary cultured pituitary cells was investigated using a dynamic perifusion system. Although epinephrine (1 mumol/l) produced an elevation in the mean value of the prolactin concentration at the onset of the perifusion, the elevation was not statistically significant, and the overall effect of ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126424
更新日期:1993-04-01 00:00:00
abstract::The effect of the antidiarrheal drug loperamide, a mu-opiate agonist, on ACTH secretion and biosynthesis, cAMP generation and phosphoinositide turnover was studied in rat anterior pituitary cell cultures. The cAMP-dependent protein kinase A pathway was stimulated with both corticotropin-releasing hormone (CRH; 2-5 nM)...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126466
更新日期:1993-06-01 00:00:00