Prolactin mRNA exists in rat hypothalamus.

Using radiolabeled DNA complementary to rat pituitary prolactin mRNA, we probed RNA gel blots from three rat tissues: pituitary, hypothalamus, and liver. Poly (A)-enriched RNA from male and female hypothalami contained a hybridizable RNA which was the same size as, though less abundant than, mature pituitary PRL mRNA. These results support the proposal that the rat brain synthesizes PRL.