HYPOTHALAMIC CONTROL OF PROLACTIN SECRETION

Neutralized acid extract of median eminence tissue from male rats and female turtles (Pseudemys scripta elegans) stimulated prolactin secretion by Pseudemys adenohypophysis in organ culture. A similar extract of turtle cerebrum was also stimulatory, but one of male rat cerebrum was not. Extract of male rat median eminence inhibited prolactin secretion by male rat adenohypophysis in vitro during the first 4 hours of incubation. However, between the fourth and twelfth hours of incubation, the male rat adenohypophyses, which were incubated with extract of male rat median eminence, secreted prolactin at a rate three times greater than that of the control incubates. The significance of these observations is discussed. © 1969.