scholarly journals Luteinizing hormone releasing factor in rat hypophysial portal blood collected during electrical stimulation of the hypothalamus

1970 ◽  
Vol 208 (1) ◽  
pp. 243-250 ◽  
Author(s):  
G. W. Harris ◽  
K. B. Ruf
Keyword(s):  
Electrical Stimulation ◽  
Luteinizing Hormone ◽  
Portal Blood ◽  
Hypophysial Portal ◽  
Stimulation Of

Vasoactive intestinal peptide in rat hypophysial portal blood: effects of electrical stimulation of various brain areas, the oestrous cycle and anaesthetics

1985 ◽  
Vol 106 (3) ◽  
pp. 275-280 ◽  
Author(s):  
A. K. Brar ◽  
G. Fink ◽  
M. Maletti ◽  
W. Rostene
Keyword(s):  
Electrical Stimulation ◽  
Vasoactive Intestinal Peptide ◽  
Peripheral Blood ◽  
Oestrous Cycle ◽  
Portal Blood ◽  
Female Rats ◽  
Female Wistar Rats ◽  
Consistent Increase ◽  
Hypophysial Portal ◽  
Stimulation Of

ABSTRACT Vasoactive intestinal peptide (VIP) was measured by radioimmunoassay in hypophysial portal and peripheral blood from adult male and female Wistar rats. The results confirmed that the concentration of VIP in hypophysial portal blood was significantly greater than in peripheral blood and showed that VIP release into portal blood was not affected by removal of the gut, the largest peripheral source of VIP. Electrical stimulation of the median eminence, several hypothalamic nuclei, the amygdala or hippocampus had no significant effect on the release of VIP into portal blood, possibly because under the conditions of the experiment the spontaneous release of VIP is already at a maximum. In female rats, the VIP released into portal blood collected between 13.00 and 18.30 h of each day of the 4-day oestrous cycle varied under different anaesthetics, and there was no consistent increase in VIP release on pro-oestrus suggesting that VIP is not involved in the pro-oestrous surge of prolactin. J. Endocr. (1985) 106, 275–280

Enhancement of Immunoreactive Somatostatin Release into Hypophysial Portal Blood by Electrical Stimulation of the Preoptic Area in the Rat*

Endocrinology ◽  
1979 ◽  
Vol 105 (6) ◽  
pp. 1416-1418 ◽  
Author(s):  
KAZUO CHIHARA ◽  
AKIRA ARIMURA ◽  
CARLOS KUBLI-GARFIAS ◽  
ANDREW V. SCHALLY
Keyword(s):  
Electrical Stimulation ◽  
Preoptic Area ◽  
Portal Blood ◽  
Hypophysial Portal ◽  
Stimulation Of

Corticotrophin-releasing factor-41, vasopressin and oxytocin release into hypophysial portal blood in the rat: effects of electrical stimulation of the hypothalamus, amygdala and hippocampus

1991 ◽  
Vol 129 (1) ◽  
pp. 99-107 ◽  
Author(s):  
L. A. Tannahill ◽  
W. J. Sheward ◽  
I. C. A. F. Robinson ◽  
G. Fink
Keyword(s):  
Electrical Stimulation ◽  
Plasma Concentrations ◽  
Direct Proof ◽  
Brain Regions ◽  
Portal Blood ◽  
Male Rats ◽  
Unilateral Stimulation ◽  
Oxytocin Release ◽  
Hypophysial Portal ◽  
Stimulation Of

ABSTRACT The role of the paraventricular nuclei (PVN), amygdala and hippocampus in the control of the hypothalamic-pituitary-adrenal axis has been studied by determining the effect of electrical stimulation of the PVN, amygdala and hippocampus on the release of corticotrophin-releasing hormone (CRF-41) and arginine vasopressin (AVP) into hypophysial portal blood and ACTH and corticosterone into peripheral blood. Adult female Wistar rats were anaesthetized with sodium pentobarbitone and stimulation was carried out through previously implanted bipolar, glass-insulated platinum electrodes. Hypophysial portal blood was collected 30 min before and 30 min during the application of the stimulus which consisted of trains (30 s on and 30 s off) of biphasic rectangular pulses with a frequency of 50 Hz, pulse width 1 ms and amplitude 1 mA. Bilateral stimulation of the PVN increased while unilateral stimulation of the amygdala decreased the release of CRF-41 into hypophysial portal blood. The threefold increase in release of CRF-41 induced by PVN stimulation correlated with a marked increase in peripheral plasma concentrations of ACTH and corticosterone. Stimulation of the hippocampus had no significant effect on CRF-41 release, and stimulation of each of the three brain regions had no effect on AVP release into portal blood. These findings were extended in a second study to compare the effects of unilateral bipolar electrical stimulation of the PVN and of the supraoptic nucleus (SON) on the release of CRF-41, AVP and oxytocin. This study was carried out on adult male rats, anaesthetized with sodium pentobarbitone, in which the stimulus was applied through previously implanted concentric stainless-steel electrodes. Unilateral stimulation of the PVN resulted in a significant increase in the release of CRF-41 and a massive increase in oxytocin release into portal blood. Increased release of oxytocin also occurred after unilateral stimulation of the SON, but CRF-41 secretion was unaffected. The secretion of AVP was unaffected by electrical stimulation of either the SON or PVN. These results (i) provide the first direct proof for the fact that the PVN is the major source of CRF-41 in hypophysial portal blood, and (ii) suggest that the release of CRF-41 may be inhibited by the amygdala. Journal of Endocrinology (1991) 129, 99–107

COMPARISON OF FOLLICLE-STIMULATING HORMONE AND LUTEINIZING HORMONE SECRETION AFTER ELECTRICAL STIMULATION OF THE PREOPTIC PART OF THE HYPOTHALAMUS IN FEMALE RATS ANAESTHETIZED WITH ETHYL CARBAMATE OR SODIUM PENTOBARBITONE

1978 ◽  
Vol 78 (1) ◽  
pp. 151-152 ◽  
Author(s):  
R. G. DYER ◽  
M. B. TER HAAR ◽  
LINDA C. MAYES
Keyword(s):  
Electrical Stimulation ◽  
Luteinizing Hormone ◽  
Follicle Stimulating Hormone ◽  
Hormone Secretion ◽  
Control Process ◽  
Female Rats ◽  
Female Rat ◽  
Luteinizing Hormone Secretion ◽  
Stimulation Of ◽  
Stimulating Hormone

A.R.C. Institute of Animal Physiology, Babraham, Cambridge, CB2 4AT (Received 17 January 1978) For over 30 years, the method by which the brain regulates the secretion of gonadotrophic hormones has been studied by electrical stimulation of those parts of the central nervous system thought to be implicated in the control process. Much of the work has been performed on the female rat. In this species, anaesthetic doses of sodium pentobarbitone, administered immediately before the pro-oestrous 'critical period', block the preovulatory surge of luteinizing hormone (LH) for 24 h. The same treatment also reduces the early phase of the pro-oestrous secretion of follicle-stimulating hormone (FSH; Daane & Parlow, 1971). Electrical stimulation of the preoptic part of the hypothalamus can overcome this blocking effect and analysis of the optimum parameters required to restore normal secretion of gonadotrophins may give some insight into the endogenous process (e.g. Everett, 1965; Fink & Aiyer, 1974;

Electrical Stimulation of Mesencephalic Noradrenergic Pathway: Effects on Luteinizing Hormone Levels in Blood of Ovariectomized and Ovariectomized, Steroid-Primed Rats*

Endocrinology ◽  
1981 ◽  
Vol 109 (3) ◽  
pp. 720-728 ◽  
Author(s):  
PETER C. K. LEUNG ◽  
GARY W. ARENDASH ◽  
DAVID I. WHITMOYER ◽  
ROGER A. GORSKI ◽  
CHARLES H. SAWYER
Keyword(s):  
Electrical Stimulation ◽  
Luteinizing Hormone ◽  
Hormone Levels ◽  
Noradrenergic Pathway ◽  
Stimulation Of

LESIONS OF THE SUPRACHIASMATIC NUCLEI AND THE SEROTONIN-DEPENDENT PHASIC RELEASE OF LUTEINIZING HORMONE IN THE RAT: EFFECTS ON DRINKING RHYTHMICITY AND ON THE CONSEQUENCES OF PREOPTIC AREA STIMULATION

1980 ◽  
Vol 84 (2) ◽  
pp. 231-236 ◽  
Author(s):  
C. W. COEN ◽  
P. C. B. MacKINNON
Keyword(s):  
Electrical Stimulation ◽  
Luteinizing Hormone ◽  
Preoptic Area ◽  
Ovariectomized Rats ◽  
Suprachiasmatic Nuclei ◽  
Lh Release ◽  
Radiofrequency Lesions ◽  
Pharmacological Manipulations ◽  
Stimulation Of ◽  
Phasic Release

Ovariectomized rats in which <7% of the suprachiasmatic nuclei had been spared by bilateral radiofrequency lesions were distinguishable from those with >40% of the nuclei by their consistent failure to show the oestrogen-induced daily surge of LH, either with or without pharmacological manipulations of serotonin (5-HT), and also by their loss of the normal rhythmicity of drinking. Minor damage to structures adjacent to the suprachiasmatic nuclei was similar in both groups. The identical facility with which electrical stimulation of the preoptic area induced LH release in the two groups of animals suggested that they were not characterized by different degrees of damage to the preopticotuberal pathway. These results are considered in relation to evidence indicating that the suprachiasmatic nuclei represent the densest concentration of 5-HT terminals in the forebrain and also the site of a mechanism involved in the generation of circadian rhythms.

Sign in / Sign up

Export Citation Format

Share Document