Abstract:
:Prolactin (PRL) secretion from the anterior pituitary is tonically controlled by the activity of the hypothalamic tuberoinfundibular dopaminergic (TIDA) system. Changes in TIDA activity have been associated with the decrease in basal PRL levels shown by hamsters exposed to a short-day photoperiod. Potential concurrent changes in the sensitivity of pituitary lactotropes to the inhibitory actions of dopamine on PRL release were investigated in tissue harvested from animals that had been preexposed to either a stimulatory, long-day 16-hour-light:8-hour-dark (16L:8D) photoperiod, or to a nonstimulatory, short-day (10L:14D) photoperiod for 8-10 weeks. Tissue was maintained in a perifusion tissue culture system and received a 1-hour pulse of varying concentrations of dopamine (DA) shortly after the equilibration period. Fractions of the media were collected every 1/2 h and PRL concentrations in each sample determined via radioimmunoassay. At the highest concentration of DA (10(-6) M), a highly significant inhibition of PRL levels was seen for both 16L and 10L pituitaries. At both mid range concentrations of DA (10(-7) and 10(-8) M), both tissue types showed a significant suppression of PRL, but the reduction was greater for tissue that had been obtained from 10L animals. At the lowest concentration of DA (10(-9) M), a significant suppression of PRL occurred for tissue harvested from 10L animals, but not for tissue taken from 16L animals. These results indicate that the responsiveness of anterior pituitary tissue to the inhibitory effects of DA are altered by photoperiod exposure, and this change is likely a consequence of changes in the characteristics of the D2 receptor population on pituitary lactotropes. Short-day-induced increases in sensitivity to the inhibitory effects of DA may be due to increases in receptor number, or to increased affinity of the D2 receptor for its ligand.
journal_name
Neuroendocrinologyjournal_title
Neuroendocrinologyauthors
Badura LLdoi
10.1159/000127153subject
Has Abstractpub_date
1996-12-01 00:00:00pages
462-6issue
6eissn
0028-3835issn
1423-0194journal_volume
64pub_type
杂志文章abstract::Tissue-specific stem cells are uncovered in a growing number of organs by their molecular expression profile and their potential for self-renewal, multipotent differentiation and tissue regeneration. Whether the pituitary gland also contains a pool of versatile 'master' cells that drive homeostatic, plastic and regene...
journal_title:Neuroendocrinology
pub_type: 杂志文章,评审
doi:10.1159/000100278
更新日期:2007-01-01 00:00:00
abstract::The effects of corticotropin-releasing factor (CRF) on GnRH release from the adult male rat mediobasal hypothalamus (MBH) and median eminence (ME) were studied in an in vitro incubation system. CRF induced a dose-related inhibition of GnRH release from both the MBH and the isolated ME, and this inhibition was blocked ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124578
更新日期:1986-01-01 00:00:00
abstract::The distribution of gamma-aminobutyric acid (GABA) nerve fibers and cell bodies in the rat hypothalamus and pituitary gland was immunohistochemically examined using antibodies against the GABA-synthesizing enzyme glutamate decarboxylase (GAD). The dense network of GAD-positive nerve fibers was observed to be essential...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123288
更新日期:1982-02-01 00:00:00
abstract::To gain further insight into the regulation of hypothalamic TRH by thyroid hormones, we measured TRH concentration in specific hypothalamic nuclei and preproTRH mRNA levels in the anterior hypothalamus. Adult male rats were decapitated 1, 7, 14 days after thyroidectomy. Micropunches by the method of Palkovitz from sev...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126131
更新日期:1992-03-01 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::Plasma and hypothalamic LHRH was measured by specific radioimmuno-assay in intact and ovariectomized rats, and the values were correlated with peripheral plasma (PP) FSH and LH titers. At most stages of the estrous cycle, plasma LHRH was either undetectable or present at very minimal values. An increase in PP LHRH con...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000122496
更新日期:1976-01-01 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::Experiments were carried out to increase the endogenous levels of TRH in brain and spinal cord. After 7 days of continuous oral ingestion of TRH analogs (D-pGlu-Leu-ProNH2, pGlu-Leu-Pro, pGlu-Pro-ProNH2, or pGlu-Leu-pyrrolidide), spinal cord and brain levels of TRH were elevated, whereas the content of TRH metabolite,...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125118
更新日期:1989-02-01 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::Electrical stimulation in the subfornical organ (SFO) alters the excitability of antidromically identified paraventricular nucleus neurons. Extracellular recordings demonstrate that the dominant effect of single stimuli delivered to the SFO on neurohypophyseal oxytocin and vasopressin containing neurons is an increase...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124015
更新日期:1984-11-01 00:00:00
abstract::Although previously considered rare, recent epidemiological studies have revealed that the incidence (3.6/100,000) and prevalence (35/100,000) of gastroenteropancreatic neuroendocrine tumors (GEP-NETs) has increased over the past few decades. Despite the progress in the understanding of GEP-NET molecular biology, ther...
journal_title:Neuroendocrinology
pub_type: 杂志文章,评审
doi:10.1159/000362339
更新日期:2014-01-01 00:00:00
abstract::Both the pituitary-adrenal axis and the pituitary-gonadal axis are under the tonic inhibitory control of endogenous opioid peptides in man. However, the precise opioid receptor involved in the modulation of these hormones remains unknown. The effect of a dose of intravenous naloxone on serum levels of luteinising horm...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124463
更新日期:1986-01-01 00:00:00
abstract::An ultradian rhythm in adrenal secretion of corticosterone has been described in awake rats using intra-adrenal microdialysis. To determine the role of the autonomic innervation of the adrenal on the expression of the corticosterone rhythm, adrenal extracellular fluid was sampled by intra-adrenal microdialysis in inta...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126645
更新日期:1994-02-01 00:00:00
abstract::Vasopressin and oxytocin modulate memory processes which effects are dissociated from the typical peripheral endocrine effects of these neuropeptides. Recently, vasopressin has been implicated in the regulation of body temperature. In view of this, experiments were designed to determine whether the antipyretic effect ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123554
更新日期:1983-10-01 00:00:00
abstract::The ability of dopamine receptor antagonists to stimulate prolactin release in rats with medial basal hypothalamic lesions was investigated. Starting levels of prolactin were elevated to approximately 400 ng/ml in animals in which the tuberoinfundibular dopaminergic neurons were completely destroyed by the lesion. In ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123188
更新日期:1981-06-01 00:00:00
abstract::We have studied some of the neuroendocrine and social correlates of dexamethasone resistance in a nonhuman primate population. Subjects were 51 male Macaca fascicularis monkeys with known behavioral histories and who had been given dexamethasone (DEX) suppression tests a week prior to killing. We compared the subset o...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126743
更新日期:1994-08-01 00:00:00
abstract::Copulatory behavior in the ovariectomized rat, i.e. the lordosis response (LR) on being mounted by a male, can be induced by administration of either estrogen alone or estrogen followed by progesterone. LR has been shown to be inhibited by lysergic acid diethylamide (LSD) in certain doses (greater than or equal to 50 ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123499
更新日期:1983-06-01 00:00:00
abstract::The known occurrence of opiates in the adrenals stimulated us to determine whether Tyr-MIF-1 (Tyr-Pro-Leu-Gly-NH2), an endogenous peptide that can act as an antiopiate, is present in these glands and whether adrenalectomy affects its concentrations in plasma. The presence of Tyr-MIF-1 in the adrenals of the rat was sh...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126403
更新日期:1993-03-01 00:00:00
abstract::Previous studies have shown that the hypothalamic concentration of pro-opiomelanocortin (POMC) mRNA and several POMC-derived peptides increases in the rat 4 weeks after orchiectomy and that this increase can be prevented by testosterone replacement. In this study, we have examined the short-term effects of orchiectomy...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125638
更新日期:1990-11-01 00:00:00
abstract::We have investigated the effects of hyperprolactinemia, produced by pituitary isografts under the kidney capsule (16-20 days), on the LH releasing action and priming effect of LH-releasing hormone (LHRH) in normal and hypogonadal (hpg) female mice. The pituitary grafts increased the plasma prolactin concentrations abo...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124585
更新日期:1986-01-01 00:00:00
abstract::The capability of the anterior pituitary gland to secrete growth hormone (GH) in response to an intravenous injection of growth hormone-releasing factor, hpGRF-44, was evaluated in male rats ranging from 22 days to 24 months of age. The increase in GH concentrations following a submaximal dose of hpGRF-44 (0.5 microgr...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123594
更新日期:1983-12-01 00:00:00
abstract:BACKGROUND:Type I gastric carcinoids (TIGCs) are neuroendocrine neoplasms arising from enterochromaffin-like cells in atrophic body gastritis. Data regarding their evolution in prospective series are scarce, thus treatment and follow-up are not codified. Our aim was to evaluate clinical outcome and recurrence in TIGCs ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000329043
更新日期:2012-01-01 00:00:00
abstract:INTRODUCTION:An increasing number of middle-aged men are being screened for low testosterone levels and the number of prescriptions for various forms of testosterone replacement therapy (TRT) has increased dramatically over the last 10 years. However, the safety of TRT has come into question with some studies suggestin...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000504445
更新日期:2020-01-01 00:00:00
abstract::As part of an assessment of endocrine influences on the actions of morphine, we have studied the effects of intracerebroventricular administration of somatostatin and thyrotropin releasing hormone (TRH) on the antinociceptive, temperature and cataleptic responses to subcutaneous morphine in both intact and hypophysect...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123586
更新日期:1983-12-01 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 effects of angiotensin II (AII) and natriuretic peptide (ANP), alone or in combination, on tuberoinfundibular dopaminergic (TIDA) neuronal activity and on serum PRL levels were examined in this study. The TIDA neuronal activity was determined by measuring 3,4-dihydroxyphenylacetic acid (DOPAC) concentration in the...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000127254
更新日期:1997-11-01 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::Adrenocorticotropic hormone (ACTH) is the major regulator of adrenocortical steroidogenesis in mammals. By comparing the sensitivity to ACTH of isolated adrenocortical cells from two sources of the same strain (Sprague-Dawley, SD) of outbred rats, we have identified a source of rat with low sensitivity to ACTH in vitr...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000054339
更新日期:1998-06-01 00:00:00
abstract::Endogenous gonadoliberin was localized by using immunocytological methods in the hypothalamic neurons which synthetize the peptide and in the hypophysial target cells. The rat tissues were fixed and frozen. Ultrathin sections were obtained by cryoultramicrotomy. In the pituitary gland, GnRH was observed in both gonado...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123300
更新日期:1982-03-01 00:00:00
abstract::Previous studies have shown that prepubertal olfactory bulbectomy will prevent the testicular regression associated with short photoperiod in golden hamsters. The gonadal regression which normally occurs in hamsters on short photoperiod is known to be due in part to an increased responsiveness of the reproductive neur...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124839
更新日期:1987-10-01 00:00:00