Abstract:
:The in vitro release of LHRH from hypothalami of adult male rats (intact, 5-day castrates, 5-day castrates replaced with various doses of testosterone) was measured under basal conditions and after the addition of KCl, the opiate antagonist naloxone or the opiate agonist DAGO to the perifusion medium. Hypothalami from all treatment groups responded to 56 mM KCl with an increased output of LHRH. LHRH release was also induced by naloxone (10(-6)M), but only from tissues derived from intacts and castrates given physiological doses of testosterone. The opiate agonist DAGO (10(-6)M) did not alter the basal release of LHRH; it, however, caused a significant decrease in the K+-induced release of LHRH from hypothalami derived from intact rats and rats replaced with physiological levels of testosterone but not from those derived from castrate rats or castrate rats replaced with small amounts of testosterone. The specificity of this latter response was shown by its reversibility with naloxone. The lack of DAGO effects upon tissues from rats with low levels of steroid implied steroid dependency of the response to opioidergic influences and indeed, the response to DAGO was restored when testosterone was replaced at physiological doses. Measurement of hypothalamic LHRH content showed no significant differences between tissues obtained from intact, castrate and testosterone-replaced castrate rats. These in vitro data support the view that the inhibitory influence of opioids upon LHRH release depends on the presence of gonadal steroids in vivo.
journal_name
Neuroendocrinologyjournal_title
Neuroendocrinologyauthors
Nikolarakis KE,Pfeiffer DG,Almeida OF,Herz Adoi
10.1159/000124662subject
Has Abstractpub_date
1986-01-01 00:00:00pages
314-9issue
3eissn
0028-3835issn
1423-0194journal_volume
44pub_type
杂志文章abstract::Insulin-deficient states are associated with an impaired function of the hypothalamic-pituitary-gonadal axis, but the mechanisms underlying hypothalamic alterations in experimental diabetes are still unknown. We investigated the effect of glucose concentrations, in the presence and absence of insulin, on LHRH release ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126257
更新日期:1992-09-01 00:00:00
abstract::Grafts of normal mouse preoptic area (POA) tissue into the third ventricle of gonadotrophin-releasing hormone (GnRH)-deficient hypogonadal (hpg) mice resulted in an elevation of pituitary GnRH receptors, an increased synthesis of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) by the pituitary gland, a...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124762
更新日期:1987-05-01 00:00:00
abstract::Pregnancy and parturition are associated with opioid-mediated elevations in maternal pain thresholds. This analgesia is subserved by a spinal cord dynorphin/kappa-opiate receptor system. During gestation, elevated pain thresholds are paralleled by a significant increase in the content of dynorphin (1-17 and 1-8) in th...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126555
更新日期:1993-09-01 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::The effect of sonicated suspensions of phosphatidylserine (PS), an acidic phospholipid, was investigated on prolactin secretion utilizing in vivo and in vitro approaches. Acute and chronic administration of PS reduced plasma prolactin levels during different phases of circadian rhythms. The phospholipid was able to in...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123261
更新日期:1981-12-01 00:00:00
abstract::The effect of catecholamines on plasma levels of immunoreactive ACTH (ACTHi), alpha-MSH (alpha-MSHi), beta-endorphin (beta-ENDi), arginine-vasopressin (AVPi) and of corticosterone (B) was studied in female rats. Intravenous infusion of the specific beta-adrenoceptor-stimulating agent l-isoproterenol in Wistar rats und...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123529
更新日期:1983-08-01 00:00:00
abstract::A prolactin (PRL) surge occurs in the female rat during proestrus in response to elevated estradiol levels. The elevated release of ovarian steroids on the day of proestrus is also associated with sexual receptivity. Mating triggers twice-daily PRL surges that supplant the proestrous PRL surge and are responsible for ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000054429
更新日期:1999-04-01 00:00:00
abstract::Interleukin-1 (IL-1) and glucocorticoid hormones represent two key mediators involved in the modulation of the neuroimmunoendocrine response to stress. IL-1 is a potent activator of the hypothalamic-pituitary-adrenal (HPA) axis in rodents. In the immune system, glucocorticoids modulate IL-1 production and a number of ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126648
更新日期:1994-02-01 00:00:00
abstract::The functions of oxytocin in the female are thought to be confined to the processes of milk ejection and parturition. In this study the role of oxytocin in the body's response to stressful stimuli has been examined. Physical immobilization of rats and forced swimming caused large increases in the secretion of the horm...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123566
更新日期:1983-10-01 00:00:00
abstract::The reuptake of dopamine into nerve terminals is the primary mechanism of inactivation of this neurotransmitter in the synaptic cleft. We report sex differences and estrous cycle variations of rat striatal dopamine uptake sites. During the estrous cycle, peak density of striatal dopamine uptake sites labelled with [3H...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126507
更新日期:1993-07-01 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::The regulation of prolactin secretion by tuberoinfundibular dopamine (DA) neurons appears to be altered in the aged rat: the concentration of prolactin in the serum increases and the activity of the tuberoinfundibular DA neurons decreases. In the young female rat a brief period of stress reduces the tuberoinfundibular...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124755
更新日期:1987-05-01 00:00:00
abstract::An enriched population of cells immunoreactive to antiserum against S-100 protein, a marker of folliculo-stellate (FS) cells in the rat pituitary, was obtained by separation of dispersed pituitary cells from adult female rats by gradient sedimentation at unit gravity. The effect of FS cells on the stimulation and inhi...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125146
更新日期:1989-04-01 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::We have investigated the hypothesis that administration of progesterone to estrogen-treated ovariectomized (OVX) rats enhances the stimulatory effects of neuropeptide Y (NPY) on the secretion of luteinizing hormone-releasing hormone (LHRH) from median eminence (ME) fragments in vitro. Adult rats were bilaterally OVX a...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125651
更新日期:1990-12-01 00:00:00
abstract::The present study investigated the effects of short-term exposure to constant light, initiated at the time of ovariectomy, on the ability of estradiol (E2) treatment alone or in conjunction with progesterone (P) to induce afternoon surges of LH and prolactin (PRL). Adult Fischer 344 rats, which had been ovariectomized...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000127009
更新日期:1995-09-01 00:00:00
abstract::To further investigate the role of serotonin in human prolactin (Prl) secretion, serotonin antagonists have been administered to healthy volunteers in basal conditions and after pretreatment with the selective blocker of dopamine receptors, pimozide (Pim). Highly significant falls (p less than 0.001) in serum Prl were...
journal_title:Neuroendocrinology
pub_type: 临床试验,杂志文章
doi:10.1159/000122753
更新日期:1978-01-01 00:00:00
abstract::We used an in vivo pharmacological approach to investigate the potential influence of serotonin (5-HT) on peptide release from the intermediate lobe (IL) of the rat pituitary. Plasma levels of alpha-melanocyte-stimulating hormone (alpha-MSH) as well as the ultrastructural appearance of IL cells were used as indicators...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125968
更新日期:1991-12-01 00:00:00
abstract::The arcuate nucleus-median eminence complex (AM) undergoes major structural and functional changes during normal puberty or if exposed to a pulse of estradiol in the prepuberal period. Those changes are expressed by increased synaptogenesis and by a drastic alteration in the feedback control of anterior pituitary glan...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124775
更新日期:1987-06-01 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::(+/-)p-Chloroamphetamine hydrochloride, at doses of 1-8 mg/kg i.p. in rats, caused a dose-related increase in serum corticosterone concentration. The increase occurred rapidly, within 30 min, and was over within 4 h. Evidence that the increase was mediated by serotonin release consisted of the following findings: (1) ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123057
更新日期:1980-08-01 00:00:00
abstract::The diuretic action of two new narcotic antagonists, oxilorphan and butorphanol, was studied in rats heterozygous for hereditary hypothalmic diabetes insipidus. Both drugs caused a prompt increase in urine volume and a decrease in urine osmolality with an associated decrease in urinary ADH excretion. The effects appea...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000122444
更新日期:1975-01-01 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::Vasoactive intestinal peptide (VIP) gene transcripts were demonstrated by RNA blot hybridization using VIP-specific RNA hybridization probes. High levels of expression were observed as early as in 16-day-old embryos. In aging rats, the VIP-mRNA levels were reduced significantly (in the cerebral cortex) as compared to ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124886
更新日期:1988-01-01 00:00:00
abstract::The differential role of porcine follicular fluid (pFF) in regulating follicle-stimulating hormone (FSH) and luteinizing hormone (LH) release in vivo in situations of different gonadotropin releasing hormone (GnRH) backgrounds was studied. In experiment 1, 2-week ovariectomized rats injected intravenously with 4, 16 o...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123891
更新日期:1984-03-01 00:00:00
abstract::Hypertension in male and aging female rodents is associated with glutamate-dependent plasticity in the hypothalamus, but existing models have failed to capture distinct transitional menopausal phases that could have a significant impact on the synaptic plasticity and emergent hypertension. In rodents, accelerated ovar...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000446073
更新日期:2017-01-01 00:00:00
abstract::To determine the possible physiological role of endogenous growth hormone-releasing factor (GRF) in the neuronal content and release of cerebral somatostatin (SS), we studied the effect of endogenous GRF blockade on the immunoreactive SS (IR-SS) content of cells and media in fetal rat cerebral cortical and hypothalami...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126118
更新日期:1992-02-01 00:00:00
abstract::Relief of symptoms can be achieved following surgery for growth hormone (GH)-secreting adenomas, as well as after pharmacological therapy with somatostatin analogs. Recently, long-acting somatostatin analog depot formulations, octreotide LAR and lanreotide SR have become available. Somatostatin analogs control GH/insu...
journal_title:Neuroendocrinology
pub_type: 杂志文章,评审
doi:10.1159/000095535
更新日期:2006-01-01 00:00:00
abstract::The storage form of prolactin (PRL) was converted into the releasable form in the lactating rat pituitary gland within 10 min of suckling by 6 pups following 4-5 h of nonsuckling on postpartum day 13-14. The characteristics of the PRL discharge from the releasable pool into the circulation was then studied using a sti...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123957
更新日期:1984-07-01 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