Abstract:
:In vivo and in vitro methods have been used to compare the effects of opioid receptor blockade on the functional activity of the hypothalamo-pituitary-gonadal axis in adult (200 g) and sexually immature (50 g) male rats. In the adult, a single injection of the mu-receptor antagonist, naloxone (500 micrograms/100 g body weight, s.c.), produced hypersecretions of luteinizing hormone (LH) and testosterone. Maximal serum concentrations of the two hormones were attained within 20 and 60 min respectively. In contrast, neither ICI 174864 (100 micrograms/100 g body weight, s.c.) nor MR2266 (150 micrograms/100 g body weight, s.c.), which block delta- and kappa-receptors respectively, stimulated pituitary-gonadal activity; indeed, like the saline vehicle, both tended to depress the serum LH concentration. The injection procedure was sufficient to activate the hypothalamo-pituitary-adrenal axis and, thus, the vehicle-treated controls exhibited significant increases in the plasma adrenocorticotrophin and serum corticosterone concentrations. These effects were enhanced by naloxone (500 micrograms/100 g body weight, s.c.) and by the kappa-opioid receptor (MR2266, 150 micrograms/100 g body weight, s.c.) but not by the delta-opioid receptor antagonist (ICI 174864, 30-100 micrograms/100 g body weight, s.c.). The increases in serum corticosterone and LH concentration induced by naloxone in adult rats were not apparent in the sexually immature (50 g) animals. To the contrary, in the young rats naloxone (250 and 500 micrograms/100 micrograms body weight, s.c.) attenuated, in a dose-dependent manner, the pronounced hypersecretion of corticosterone induced by the vehicle injection. The higher dose of the antagonist (500 micrograms/100 g body weight, s.c.) also overcame the significant reductions in serum LH evident 20 (p less than 0.05) and 40 (p less than 0.01) min after the saline injection but the lower dose (250 micrograms/100 g body weight, s.c.) was ineffective in this respect. In vitro, hypothalami from both adult and sexually immature rats responded to the addition of naloxone (10(-8)-10(-6) M) to the incubation medium with significant (p less than 0.01) concentration-dependent increases in the release of gonadotrophin-releasing hormone (GnRH). In contrast, ICI 174864 (10(-7)-10(-6) M) and MR2266 (10(-7)-10(-6) M) had little effect on the secretion of the releasing hormone by hypothalami from rats of either group although, at the highest concentration tested, MR2266 (10(-6) M) precipitated a small increase in GnRH release from hypothalami from adult rats.(ABSTRACT TRUNCATED AT 400 WORDS)
journal_name
Neuroendocrinologyjournal_title
Neuroendocrinologyauthors
Leposavic G,Cover PO,Buckingham JCdoi
10.1159/000125777subject
Has Abstractpub_date
1991-06-01 00:00:00pages
579-88issue
6eissn
0028-3835issn
1423-0194journal_volume
53pub_type
杂志文章abstract:BACKGROUND:Little information is available concerning prognostic factors for bronchopulmonary large cell neuroendocrine carcinomas (BP-LCNECs) and even less is known about combined LCNECs (Co-LCNECs). We investigated whether an integrated morphological, immunohistochemical, and molecular approach could be used for thei...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000508376
更新日期:2020-05-04 00:00:00
abstract::The purpose of the present study was to examine whether repetitive intravenous injections of L-glutamic acid (Glu), like those of N-methyl-D,L-aspartic acid (NMA), are able to elicit a sustained train of gonadotropin releasing hormone (GnRH) discharges from the hypothalamus of the prepubertal male monkey. In order to ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126186
更新日期:1992-06-01 00:00:00
abstract::An electrophysiological investigation was conducted on the connection of medial preoptic neurons with the median eminence and the basal and corticomedial amygdala in pentobarbital anesthesized male Sprague-Dawley rats. Of 411 medial preoptic neurons tested with median eminence stimuli, antidromic responses (mean laten...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123237
更新日期:1981-01-01 00:00:00
abstract::Dehydration is a classic homeostatic stressor in rats that leads to a series of endocrine responses including stimulation of the hypothalamo-pituitary-adrenal (HPA) axis. During the last decade, it has been well established that perinatal food restriction is associated with the onset of diseases in adults. Our previou...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000078098
更新日期:2004-01-01 00:00:00
abstract::We studied the effect that beta-endorphin (beta END) might have at the median eminence (ME) on luteinizing hormone (LH)-releasing hormone (LHRH) during the ovulatory cycle of domestic hens. Thus, we assessed (a) the immunocytochemical distribution of beta END and LHRH in the hen ME, (b) the temporal changes in ME and ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000126381
更新日期:1993-01-01 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::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::5-hydroxytryptamine (5-HT) synthesis [accumulation of 5-hydroxytryptophan (5-HTP) following inhibition of aromatic L-amino acid decarboxylase with NSD 1015] and metabolism [concentration of the primary metabolite of 5-HT, 5-hydroxyindole-3-acetic acid (5-HIAA)] were measured in the suprachiasmatic (SCN), medial preopt...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123878
更新日期:1984-02-01 00:00:00
abstract::Circadian rhythm of blood corticosterone in adrenalectomized rats with (AT rat) or without adrenal autotransplants was investigated. Blood samples were obtained individually at 4-hour intervals for a 24-hour period per week for 5-7 consecutive weeks by the tail tip incision method. Corticosterone responses of the auto...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000123294
更新日期:1982-03-01 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::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::The aim of this study was to examine the occurrence of endogenous oscillations of Per1, Per2, Bmal1 and Rev-erbα genes in rat pineal explants and to investigate their regulation by adrenergic ligands. Our results show a significant and sustained rhythm of Per2,Bmal1 and Rev-erbα gene expression for up to 48 h in cultu...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000327430
更新日期:2011-01-01 00:00:00
abstract::The effects of intracerebroventricular (i.c.v.) or intracarotid (i.a.) administration of amylin (AMY) on growth hormone (GH) release induced by GH-releasing hormone (GHRH) were examined in conscious male rats. Amylin (25 ng-5 micrograms/rat, i.c.v. or 10 micrograms/rat, i.a.) was administered 10 min before GHRH (2 mic...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000127019
更新日期:1995-09-01 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 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::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::Follicle-stimulating hormone (FSH) is involved in the regulation and maintenance of gametogenesis. It exists in multiple molecular forms with different oligosaccharide structures which in turn are influenced by the hormonal milieu. Previous studies from our laboratory demonstrated that antiandrogen administration to i...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000054484
更新日期:1999-10-01 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:BACKGROUND:Synaptic plasticity is the neuronal capacity to modify the function and structure of dendritic spines (DS) in response to neuromodulators. Sex steroids, particularly 17β-estradiol (E2) and progesterone (P4), are key regulators in the control of DS formation through multiprotein complexes including WAVE1 prot...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000503310
更新日期:2020-01-01 00:00:00
abstract:BACKGROUND:To evaluate the construct and criterion validity of the Tuebingen Cushing's disease quality of life inventory (Tuebingen CD-25) for application in patients treated for Cushing's disease (CD). METHODS:A total of 176 patients with adrenocorticotropin hormone-dependent CD (144 of them female, overall mean age ...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000431022
更新日期:2015-01-01 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 push-pull perfusion technique, in conjunction with specific radioimmunoassays, was used to monitor the release of both arginine vasopressin (AVP) and oxytocin (OXT) within distinct limbic brain areas of conscious female rats. In pregnant rats near term, the release of AVP was greater than that of virgin rats in bo...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000125917
更新日期:1991-10-01 00:00:00
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...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000076631
更新日期:2004-02-01 00:00:00
abstract::The effects of acute and chronic administration of a combination of lynestrenol-mestrenol, a widely employed contraceptive medication, on the dopaminergic system of the rat forebrain and striatum were investigated to better understand the biochemical basis of the neurological side-effects of steroid contraceptive drug...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000122643
更新日期:1976-01-01 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::Adenylate cyclase activity was studied in anterior pituitary homogenates from young adult (6 months) and old (20 and 24 months) male rats. Basal, NaF-, GTP-, 5'-guanylimidodiphosphate (Gpp(NH)p)- and forskolin-stimulated activities were similar in the three groups, implying that the stimulatory guanyl nucleotide regul...
journal_title:Neuroendocrinology
pub_type: 杂志文章
doi:10.1159/000124682
更新日期:1986-01-01 00:00:00
abstract::Hypophysitis is a relatively rare disease that exerts a strong autoimmune component encompassing different etiologies. Immunomodulatory drugs, such as interferon-α, are known to rarely induce hypophysitis. In recent years, a large number of new biological and immunomodulatory agents have been introduced into clinical ...
journal_title:Neuroendocrinology
pub_type: 杂志文章,评审
doi:10.1159/000480086
更新日期:2018-01-01 00:00:00
abstract::Overt Cushing's syndrome is a rare disorder with an annual incidence of 2-3/million of which benign adrenal adenomas account for 0.6/million. The female:male ratio is 3:1. Preliminary data indicate a high proportion of subclinical Cushing's syndrome in certain risk populations such as patients with type 2 diabetes or ...
journal_title:Neuroendocrinology
pub_type: 杂志文章,评审
doi:10.1159/000314297
更新日期:2010-01-01 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: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