Prostaglandin F_{2 alpha} Stimulates Vasopressin and Oxytocin Release from Isolated Rat Neurointermediate Lobe¹)

Abstract

Prostaglandin F2 alpha (1.4 X 10(-7) - 1.4 X 10(-5) M) increases vasopressin and oxytocin release from isolated rat neurointermediate lobes. Prostaglandin F2 alpha may be therefore supposed to serve as a modulatory factor for the vasopressin and oxytocin release, the respective processes being localized, at least in part, in the neurohypophysis.

Prostaglandin F2α receptor in the neurohypophysis of hens

“…However, a possibility of the direct action of PGF 2α on the neurohypophysis has not been examined. In rats, it was reported that the PGF 2α increases vasopressin and oxytocin releases from isolated neurointermediate lobes in vitro (Bojanowska and Guzek, 1989). The present study was performed to obtain evidence for a direct action of PGF 2α on the neurohypophysis of the hen as indicated by the presence of a receptor and, if obtained, to determine whether the bindings of PGF 2α receptor are different between laying hens and nonlaying hens and to determine whether PGF 2α binding to the receptor changes with relation to oviposition.…”

Inhibition of Prostaglandin Synthesis and the Release of Vasopressin and Oxytocin from the Rat Neurohypophysis: In Vitro Studies1)

“…Prostaglandins are known to affect the secretion of both neurohypophysial hormones in vivo (Ellendorf et al, 1978;Fujimoto et al, 1978;Hoffman et al, 1982;Leksell, 1976;Prilusky and Deis, 1976;Yamamoto et al, 1976) as well as in vitro (Bojanowska and Guzek, 1989;Gagnon et al, 1973;Ishikawa et al, 1981;Negro-Vilar et al, 1985). Suppression of prostaglandin synthesis was reported to be followed by changes of the neurohypophysial function: both meclofenamate (Walker, 1983) and indomethacin (Yamamoto et al, 1976), administered intravenously in the dog, were observed to lower the plasma vasopressin level.…”