title: Isoprenaline and forskolin increase evoked vasopressin release from rat pituitary.
abstract: Isolated neurointermediate lobes of rat pituitaries were incubated in Krebs solution. The vasopressin release evoked by electrical stimulation (0.2 ms, 80 V, 15 Hz, 10 s trains at 10 s intervals for a total of 10 min) was completely inhibited by tetrodotoxin. Isoprenaline increased the evoked vasopressin release to a maximum of 60% (EC50 10 nM) and this effect was antagonized surmountably by propranolol. Forskolin increased the vasopressin release by 98%. These results suggest the presence within the neurohypophysis of a beta-adrenoceptor-linked adenylate cyclase facilitating vasopressin secretion.
mesh_terms: D000818:Animals; D005576:Colforsin; D004224:Diterpenes / Q000494:pharmacology*; D004558:Electric Stimulation; D005260:Female; D007545:Isoproterenol / Q000494:pharmacology*; D010902:Pituitary Gland / Q000378:metabolism* / Q000502:physiology; D010904:Pituitary Gland, Posterior / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013268:Stimulation, Chemical; D014667:Vasopressins / Q000378:metabolism*
chemical_list: D004224:Diterpenes; D014667:Vasopressins; D005576:Colforsin; D007545:Isoproterenol