Neuropeptide Y injected into the supraoptic nucleus causes secretion of vasopressin in the unanesthetized rat.
Injection of neuropeptide Y (NPY, 0.01-1.0 nmol in 0.25 microliter vehicle) into the supraoptic nucleus of unanesthetized rats increased plasma vasopressin, measured by radioimmunoassay, to a maximum of 90 +/- 18 ng/liter. Injections of vehicle or somatostatin did not increase plasma vasopressin, nor did injections of NPY into the amygdala. Double-labelling immunohistochemical studies demonstrated that fibers containing NPY-like immunoreactivity form a close association with vasopressin immunoreactive perikarya in the supraoptic nucleus. It appears that NPY may directly excite vasopressin-containing neurons causing secretion of vasopressin.
D000818:Animals; D006651:Histocytochemistry; D008297:Male; D009478:Neuropeptide Y / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013495:Supraoptic Nucleus / Q000187:drug effects* / Q000378:metabolism; D014667:Vasopressins / Q000097:blood / Q000378:metabolism*
D009478:Neuropeptide Y; D014667:Vasopressins