Suppression of salt intake in the rat by neurokinin A: comparison with the effect of kassinin.
The present study investigates the effect of the mammalian tachykinin neurokinin A on salt intake in the rat. Intracerebroventricular injection of neurokinin A inhibited salt intake elicited by sodium depletion, by subchronic deoxycorticosterone treatment and by adrenalectomy. It also inhibited the need-free salt intake of female rats that had been previously depleted of sodium. Since different brain mechanisms elicit salt intake in these experimental models, it is concluded that neurokinin A exerts a general antinatriorexic effect. Apparently, its inhibitory effect on salt intake is not due to malaise or competing behaviors, as shown by the fact that the doses of neurokinin A which suppress salt intake do not suppress milk intake. In comparison to the amphibian tachykinin kassinin, neurokinin A possesses a similar spectrum of antinatriorexic activities, but is markedly less potent and less effective in all the experimental models investigated. These findings suggest that activation of neurokinin A receptors cannot solely account for the potent antinatriorexic effect of kassinin and of other nonmammalian tachykinins.
Massi
M
M
Institute of Pharmacology, University of Camerino, Italy.
Epstein
A N
AN
D000315:Adrenalectomy; D000818:Animals; D001066:Appetite / Q000187:drug effects*; D002552:Cerebral Ventricles / Q000187:drug effects / Q000502:physiology*; D003900:Desoxycorticosterone / Q000494:pharmacology; D005260:Female; D007276:Injections, Intraventricular; D015286:Kassinin / Q000008:administration & dosage / Q000494:pharmacology*; D015288:Neurokinin A / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D012982:Sodium, Dietary
D012982:Sodium, Dietary; D003900:Desoxycorticosterone; D015286:Kassinin; D015288:Neurokinin A