A study was made of the effects of manipulating brain dopaminergic activity upon drinking induced by intracerebroventricular administration of angiotensin II or carbachol. Non-specific lesions induced by injecting 6-hydroxydopamine (6-OHDA) into the cerebroventricles caused a significant reduction in angiotensin-induced thirst without affecting carbachol drinking. specific 6-OHDA-induced lesions of the dopaminergic nigro-striatal pathway also attenuated the angiotensin-induced response, while unilateral lesions reduced and bilateral lesions almost completely abolished the effect. Again, the response to carbachol was unaffected. Chronic haloperidol treatment increased behavioural responses to the dopamine agonist apomorphine and significantly stimulated angiotensin-induced drinking without affecting response to carbachol. These studies provide support for the hypothesis that a dopaminergic event is involved in the angiotensin-induced thirst response and point to the need for a functioning dopaminergic nigro-striatal pathway for the full expression of this response.
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http://dx.doi.org/10.1007/BF00429214 | DOI Listing |
J Renin Angiotensin Aldosterone Syst
December 2007
Department of Physiological Sciences, Institute of Biology, Federal Rural University of Rio de Janeiro, Seropédica, RJ, Brazil.
Objective: Considering the controversial data regarding the role of the brain renin-angiotensin system (RAS) on the thirst and sodium appetite in ovariectomised rats, we aimed to evaluate the role of the brain angiotensin II (Ang II) AT1-receptor on the nocturnal fluids intake.
Materials And Methods: Groups of Wistar female rats were ovariectomised and chronically given oestrogen or vehicle to evaluate its influence on effects induced by i.c.
Bull Exp Biol Med
July 2006
Laboratory of Motivation Physiology, P. K. Anokhin Institute of Physiology, Russian Academy of Medical Sciences, Moscow. ru
Systemic administration of angiotensin II after carotid glomectomy produced a less pronounced dipsogenic effects (consumption of water and NaCl solution) compared to sham-operated control animals. Injection of angiotensin II into the lateral cerebral ventricles of the same glomectomized rats increased water and NaCl consumption to a level surpassing that of sham-operated animals. The number of drinking acts and comfortable grooming acts decreased in glomectomized animals after systemic administration of angiotensin II, but increased after its intracerebral injection compared to the control.
View Article and Find Full Text PDFBull Exp Biol Med
November 2004
Laboratory of Motivation Physiology, P. K. Anokhin Institute of Physiology, Russian Academy of Medical Sciences, Moscow, Russia.
Carotid glomectomy in rats reduced daily water consumption and increased daily consumption of NaCl solution. Sham operation did not modify water and salt consumption. Intraperitoneal injection of angiotensin-II did not stimulate drinking motivation in the majority of rats subjected to carotid glomectomy.
View Article and Find Full Text PDFAm J Physiol Regul Integr Comp Physiol
November 2001
Department of Psychology, University of Iowa, Iowa City, Iowa 52242-1407, USA.
We examined the effects of hypotension and fluid depletion on water and sodium ingestion in rats in response to intracerebroventricular infusions of ANG II. Hypotension was produced by intravenous infusion of the vasodilator drug minoxidil (25 microg x kg(-1) x min(-1)) concurrently with the angiotensin-converting enzyme inhibitor captopril (0.33 mg/min) to prevent endogenous ANG II formation.
View Article and Find Full Text PDFRegul Pept
December 1994
Department of Physiology, College of Medicine, University of Florida, Gainesville 32610, USA.
Antisense oligodeoxynucleotides (AS-ODN) to AT1 receptor mRNA inhibit high blood pressure in Spontaneously Hypertensive Rats (SHR) when injected into the brain. The effect is presumably through inhibition of the actions of brain angiotensin II (Ang II). Central injection of Ang II elicits several physiological responses including release of vasopressin and motivation to drink.
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