Prolactin Release induced by Prostaglandin F2α in Pregnant Rats

PROSTAGLANDIN (PGF2α) induces lactogenesis and advanced parturition when injected into pregnant rats¹. A luteolytic effect of PGF2α has also been demonstrated in pseudopregnant and pregnant rats^3,4, normal guinea-pig⁵, autotransplanted sheep ovary⁶ and pregnant hamster⁷. The decrease of plasma progesterone concentration before parturition^8–10 will trigger the release of prolactin and other hormones from the hypophysis and induce lactogenesis^11–13 which in the normal pregnant rat occurs around 12 h before parturition¹³.