scholarly journals Opiate regulation of estradiol-2-hydroxylase in brains of male rats: mechanism for control of pituitary hormone secretion.

1980 ◽  
Vol 77 (5) ◽  
pp. 2574-2576 ◽  
Author(s):  
J. Fishman ◽  
B. I. Norton ◽  
E. F. Hahn
Keyword(s):  
Hormone Secretion ◽  
Male Rats ◽  
Pituitary Hormone

Effects of zinc and cadmium administration on pituitary hormone secretion in adult male rats

1996 ◽  
Vol 88 ◽  
pp. 62 ◽  
Author(s):  
Eva Alvarez ◽  
Antonio Blanco ◽  
Nuria Márquez ◽  
Ana I. Esquifino ◽  
Anunciación Lafuente
Keyword(s):  
Adult Male ◽  
Hormone Secretion ◽  
Male Rats ◽  
Pituitary Hormone

Central opioid receptors mediate glucoprivic inhibition of pituitary LH secretion

1997 ◽  
Vol 272 (4) ◽  
pp. E517-E522 ◽  
Author(s):  
K. P. Briski
Keyword(s):  
Receptor Antagonist ◽  
Opioid Receptor ◽  
Hormone Secretion ◽  
Male Rats ◽  
Pituitary Hormone ◽  
Intracerebroventricular Administration ◽  
Receptor Antagonists ◽  
Opioid Receptor Antagonist ◽  
Opioid Receptor Antagonists

The present studies investigated the significance of glucoprivic metabolic signals, particularly those of central origin, to the regulation of pituitary luteinizing hormone (LH). Groups of gonadectomized (GDX) adult male rats were treated with 2-deoxy-D-glucose (2-DG), an inhibitor of glycolysis, by either intravenous (50, 100, or 200 mg/kg) or intracerebroventricular (5, 20, or 100 microg/rat) administration. Systemic drug treatment caused a significant decrease in mean plasma LH levels compared with saline-treated controls. Intracerebroventricular administration of 2-DG was also efficacious in suppressing circulating LH; animals treated with either of the two highest doses of the drug exhibited a significant reduction in plasma LH. In vitro studies examined direct effects of 2-DG on pituitary gonadotrope secretory activity. Exposure of anterior pituitary tissue to 2-DG during short-term perfusion had no significant impact upon either basal or gonadotropin-releasing hormone-stimulated LH release. Finally, groups of GDX rats were pretreated by intracerebroventricular administration of either the nonselective opioid receptor antagonist, naltrexone, or the selective mu-opioid receptor antagonist, beta-funaltrexamine (beta-FNA), before intravenous injection of 2-DG. Both receptor antagonists were observed to attenuate the suppressive effects of 2-DG on circulating LH in these animals. In summary, treatment of GDX rats with the glucose antimetabolite, 2-DG, decreased plasma LH, suggesting that metabolic signaling of cellular glucose oxidation is of physiological importance to the regulation of pituitary hormone secretion. Findings that plasma LH was diminished in animals treated intracerebroventricularly with 2-DG implicate central glucoprivic receptors in neuroendocrine mechanisms governing the reproductive endocrine axis. Attenuation of 2-DG-induced decreases in circulating LH by opioid receptor antagonists suggests that these receptors, particularly the mu-subtype, mediate central effects of glucoprivation on circulating LH.

scholarly journals Altered pituitary hormone secretion in male rats exposed to bisphenol A

2006 ◽  
Vol 10 (1) ◽  
pp. 24
Author(s):  
AM Gharravi ◽  
R Ghorbani ◽  
M Khazaei ◽  
PourA Motabbad ◽  
M Al Agha ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Hormone Secretion ◽  
Male Rats ◽  
Pituitary Hormone

Effect of moderate alcohol consumption on pituitary-hormone secretion in Wistar male rats

2006 ◽  
Vol 27 (1) ◽  
pp. 103-104
Author(s):  
L.E. Díaz ◽  
J. Romeo ◽  
E. Nova ◽  
S. Gómez ◽  
P. Cano ◽  
...  
Keyword(s):  
Alcohol Consumption ◽  
Hormone Secretion ◽  
Male Rats ◽  
Pituitary Hormone ◽  
Moderate Alcohol Consumption ◽  
Wistar Male Rats

A role for inhibin in the control of follicle-stimulating hormone secretion in male rats

Life Sciences ◽  
1985 ◽  
Vol 36 (9) ◽  
pp. 889-899 ◽  
Author(s):  
Henry M. Jones ◽  
Constance L. Wood ◽  
Michael E. Rush
Keyword(s):  
Follicle Stimulating Hormone ◽  
Hormone Secretion ◽  
Male Rats ◽  
Stimulating Hormone

Differential effects of passive immunization with somatostatin antiserum on adenohypophysial hormone secretions in starved rats

1986 ◽  
Vol 109 (2) ◽  
pp. 169-174 ◽  
Author(s):  
J. N. Hugues ◽  
A. Enjalbert ◽  
E. Moyse ◽  
C. Shu ◽  
M. J. Voirol ◽  
...  
Keyword(s):  
Binding Capacity ◽  
Hormone Secretion ◽  
Plasma Concentrations ◽  
Passive Immunization ◽  
Negative Control ◽  
Prolactin Secretion ◽  
Male Rats ◽  
Minimal Effective Dose ◽  
Gh Secretion

ABSTRACT The role of somatostatin (SRIF) on adenohypophysial hormone secretion in starved rats was reassessed by passive immunization. Because of the absence of pulsatile GH secretion in starved rats, the effects of the injection of SRIF antiserum on GH levels can be clearly demonstrated. To determine whether starvation modifies the sensitivity of the adenohypophysis to SRIF, we measured 125I-labelled iodo-N-Tyr-SRIF binding. There was no difference in the dissociation constant (Kd) nor in the maximal binding capacity (Bmax) in fed (n = 15) and starved (n = 15) animals (Kd = 0·38 ± 0·09 (s.e.m.) and 0·45 ± 0·09 nmol; Bmax = 204 ± 39 and 205 ± 30 fmol/mg protein respectively). Administration of SRIF antiserum resulted in a dose-dependent increase in plasma concentrations of GH, TSH and prolactin. The minimal effective dose of SRIF antiserum was 50 μl for GH, 100 μl for TSH and 200 μl for prolactin. Our results show that: (1) starvation does not modify adenohypophysial SRIF-binding sites, (2) in starved male rats endogenous SRIF exerts a negative control on prolactin secretion in vivo and (3) sensitivity to endogenous SRIF seems to be different for each hypophysial cell type. J. Endocr. (1986) 109, 169–174

A novel technique for measuring hypothalamic and pituitary hormone secretion rates from collection of pituitary venous effluent in the normal horse

1987 ◽  
Vol 113 (2) ◽  
pp. 183-192 ◽  
Author(s):  
C. H. G. Irvine ◽  
S. L. Alexander
Keyword(s):  
Hormone Secretion ◽  
Pituitary Hormones ◽  
Blood Collection ◽  
Pituitary Hormone ◽  
Blood Samples ◽  
Novel Technique ◽  
Time Period ◽  
Normal Functional ◽  
Gonadotrophin Releasing Hormone ◽  
Secretion Rates

ABSTRACT We have described a novel technique for collecting pituitary venous effluent in the horse by placing a cannula in the intercavernous sinus close to the outlet of the pituitary veins using a venous pathway unique to equids. Cannula placement and blood collection are carried out painlessly in fully conscious, ambulatory, unstressed animals. There is no interference to hypothalamic, pituitary or target organ function. The blood collected contains readily measurable concentrations of gonadotrophin-releasing hormone, and LH concentrations which can be up to 40 times those in concurrent peripheral blood samples. Four millilitre blood samples, a quantity which permits simultaneous measurement of many hypothalamic and pituitary hormones, can be collected at 2-min intervals for several days. Intercavernous sinus blood flow can be calculated allowing secretion rates of hypothalamic and pituitary hormones to be determined for any time-period. This model is uniquely useful for investigating the normal functional characteristics of several neuroendocrine and endocrine systems. J. Endocr. (1987) 113, 183–192

Vasopressin as a neuroendocrine regulator of anterior pituitary hormone secretion

1993 ◽  
Vol 129 (6) ◽  
pp. 489-496 ◽  
Author(s):  
Andreas Kjær
Keyword(s):  
Arginine Vasopressin ◽  
Mode Of Action ◽  
Anterior Pituitary ◽  
Hormone Secretion ◽  
Pituitary Hormones ◽  
Pituitary Hormone ◽  
Anterior Pituitary Hormones ◽  
Anterior Pituitary Hormone

Secretion of the anterior pituitary hormones adrenocorticotropin (ACTH), β-endorphin and prolactin (PRL) is complex and involves a variety of factors. This review focuses on the involvement of arginine-vasopressin (AVP) in neuroendocrine regulation of these anterior pituitary hormones with special reference to receptor involvement, mode of action and origin of AVP. Arginine-vasopressin may act via at least two types of receptors: V1− and V2−receptors, where the pituitary V1−receptor is designated V1b. The mode of action of AVP may be mediating, i.e. anterior pituitary hormone secretion is transmitted via release of AVP, or the mode of action may be permissive, i.e. the presence of AVP at a low and constant level is required for anterior pituitary hormones to be stimulated. Under in vivo conditions, the AVP-induced release of ACTH and β-endorphin is mainly mediated via activation of hypothalamic V1− receptors, which subsequently leads to the release of corticotropin-releasing hormone. Under in vitro conditions, the AVP-stimulated release of ACTH and β-endorphin is mediated via pituitary V1b− receptors. The mode of action of AVP in the ACTH and β-endorphin response to stress and to histamine, which is involved in stress-induced secretion of anterior pituitary hormones, is mediating (utilizing V1− receptors) as well as permissive (utilizing mainly V1− but also V2−receptors). The AVP-induced release of PRL under in vivo conditions is conveyed mainly via activation of V1−receptors but V2−receptors and probably additional receptor(s) may also play a role. In stress- and histamine induced PRL secretion the role of AVP is both mediating (utilizing V1 −receptors) and permissive (utilizing both V1− and V2− receptors). Arginine-vasopressin may be a candidate for the PRL-releasing factor recently identified in the posterior pituitary gland. Arginine-vasopressin of both magno- and parvocellular origin may be involved in the regulation of anterior pituitary hormone secretion and may reach the corticotrophs and the lactotrophs via three main routes: the peripheral circulation, the long pituitary portal vessels or the short pituitary portal vessels.

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