Dissociation in the effects of the D2/D3 dopaminergic agonist quinpirole on drinking and on vasopressin levels in the rat.
In the present study, we investigated the role of vasopressin in the development of quinpirole-induced hyperdipsia in the rat. We report that: (1), an acute intraperitoneal (i.p.) injection of 0.56 mg/kg of quinpirole increased plasma vasopressin (radioimmunoassay) at 15 min but not at 30 or 120 min; (2), nine daily injections of quinpirole (0.56 mg/kg, i.p.) progressively increased water intake and diuresis for a period of several hours after each treatment; (3), quinpirole hyperdipsia was associated with apparently normal levels of vasopressin (which might be considered inappropriately high in the presence of excessive drinking); (4), quinpirole reduced vasopressin and oxytocin, but not angiotensin, immunoreactivity in the supraoptic nucleus. These findings suggest that quinpirole hyperdipsia is a sound animal model of psychotic polydipsia.
Badiani
Aldo
A
Department of Human Physiology and Pharmacology, University of Rome La Sapienza, 5 Piazzale Aldo Moro, 00185 Rome, Italy. aldo.badiani@uniroma1.it
Vaccaro
Rosa
R
Burdino
Rosetta
R
Casini
Arianna
A
Valeri
Pacifico
P
Renda
Tindaro G
TG
Nencini
Paolo
P
D000818:Animals; D004231:Diuresis / Q000187:drug effects; D018491:Dopamine Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D004326:Drinking / Q000187:drug effects*; D007274:Injections, Intraperitoneal; D008297:Male; D010121:Oxytocin / Q000037:antagonists & inhibitors; D019257:Quinpirole / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017448:Receptors, Dopamine D2 / Q000819:agonists*; D050637:Receptors, Dopamine D3; D013495:Supraoptic Nucleus / Q000378:metabolism; D013997:Time Factors; D014667:Vasopressins / Q000037:antagonists & inhibitors / Q000097:blood* / Q000378:metabolism
D018491:Dopamine Agonists; C493595:Drd3 protein, rat; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D014667:Vasopressins; D019257:Quinpirole; D010121:Oxytocin