Participation of noradrenergic neurotransmission in angiotensin III-induced dipsogenic behavior in the rat.
Conscious, adult, male Sprague-Dawley rats, instrumented with in-dwelling cannula for drug application into the lateral cerebral ventricle, were used to evaluate the participation of noradrenergic neurotransmission in angiotensin III (AIII)-induced dipsogenic behavior. Intracerebroventricular (i.c.v.) administration of AIII (20, 40 or 80 pmol) elicited a robust and dose-related drinking response. Chemical lesion produced by i.c.v. injection of the catecholaminergic neurotoxin, 6-hydroxydopamine (25 micrograms x 3), or the selective noradrenergic neurotoxin, N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (250 micrograms), promoted significant antagonization of the dipsogenic behavior produced by AIII (40 or 80 pmol, i.c.v.). Under equimolar doses (3.25 or 6.50 nmol), the specific alpha 1-adrenoceptor blocker, prazosin, antagonized; the specific alpha 2-adrenoceptor antagonist, yohimbine, enhanced; and the nonselective alpha-adrenoceptor blocker, phentolamine, elicited minimal action, on AIII (40 pmol)-induced drinking response. These results suggest that central noradrenergic neurotransmission may participate actively in AIII-induced dipsogenesis, in a process that may involve both alpha 1- and alpha 2-adrenoceptors.
Chan
J Y
JY
Department of Medical Research, Taipei Veterans General Hospital, Taiwan, Republic of China.
Pan
S
S
Chan
S H
SH
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000804:Angiotensin II / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001596:Benzylamines / Q000494:pharmacology; D002217:Carbachol / Q000008:administration & dosage / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004327:Drinking Behavior / Q000187:drug effects*; D004347:Drug Interactions; D006892:Hydroxydopamines / Q000494:pharmacology*; D007275:Injections, Intravenous; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology / Q000502:physiology*; D016627:Oxidopamine; D010646:Phentolamine / Q000008:administration & dosage / Q000494:pharmacology; D011224:Prazosin / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000145:classification / Q000502:physiology; D013566:Sympathomimetics / Q000494:pharmacology; D009435:Synaptic Transmission / Q000187:drug effects* / Q000502:physiology; D015016:Yohimbine / Q000008:administration & dosage / Q000494:pharmacology
D000317:Adrenergic alpha-Antagonists; D001596:Benzylamines; D006892:Hydroxydopamines; D011942:Receptors, Adrenergic, alpha; D013566:Sympathomimetics; D000804:Angiotensin II; D015016:Yohimbine; D016627:Oxidopamine; D002217:Carbachol; C012102:DSP 4; D009638:Norepinephrine; D011224:Prazosin; D010646:Phentolamine