Effect of substances influencing brain serotonergic transmission on plasma vasopressin levels in the rat.
Studies were carried out in the rat to investigate whether serotonin (5-HT) is involved in the regulation of vasopressin (ADH) release. For this purpose plasma ADH levels were measured in rats treated with drugs enhancing 5-HT transmission, such as d-fenfluramine and quipazine and with 5-HT depleting drugs, p-chlorophenylalanine (PCPA) and 5,7-dihydroxytryptamine (5,7-DHT). Forebrain 5HT, noradrenaline (NA) and dopamine (DA) were also measured. d-Fenfluramine and quipazine induced dose-related increases in plasma ADH levels in normohydrated rats. The effects of quipazine and d-fenfluramine were prevented by PCPA, indicating that 5-HT transmission was required for the biologic response. 5,7-DHT and PCPA pretreatment decreased forebrain 5-HT content and prevented ADH increases involved by water deprivation, suggesting that 5HT is necessary for the hormonal response to osmotic stimuli. The results summarized imply that serotonin may have a role in the physiological release of ADH from neurohypophysis.
Iovino
M
M
Steardo
L
L
D015116:5,7-Dihydroxytryptamine / Q000494:pharmacology; D000818:Animals; D001921:Brain / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D010134:Fenclonine / Q000494:pharmacology; D005277:Fenfluramine / Q000494:pharmacology; D008297:Male; D011814:Quipazine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000502:physiology*; D014667:Vasopressins / Q000097:blood*
D014667:Vasopressins; D005277:Fenfluramine; D015116:5,7-Dihydroxytryptamine; D012701:Serotonin; D011814:Quipazine; D010134:Fenclonine