PERMISSIVE ROLE OF CORTICOTROPIN-RELEASING FACTOR IN THE ACUTE STRESS-INDUCED PROLACTIN-RELEASE IN FEMALE RATS

The present study examined the role of corticotropin-releasing factor (CRF) in the acute stress-induced release of prolactin (PRL) in ovarie ctomized estrogen-primed female rats. Acute immobilization stress indu ced a marked increase in serum PRL levels in animals treated with sali ne intraventricularly (icy). However, a prior icy injection of alpha-h elical CRF(9-41), a CRF antagonist, completely eliminated the immobili zation-induced PRL release in the majority of animals, providing evide nce for involvement of CRF in the acute stress-induced PRL release. On the other hand, an icy injection of CRF did not affect basal PRL rele ase at any dose in non-stressed animals, suggesting that the peptide p lays a permissive role which enables other undefined stress mediator(s ) to stimulate PRL release.