ROLE OF ENDOGENOUS CRF IN THE MEDIATION OF NEUROENDOCRINE AND BEHAVIORAL-RESPONSES TO CALCITONIN-GENE-RELATED PEPTIDE IN RATS

In the present study, the possible role of cortocotropin-releasing hor mone (CRF) in the action of calcitonin gene-related peptide (CGRP) on the pituitary-adrenal axis and open-field activity of rats was tested. CGRP administered into the lateral brain ventricle led to a dose-depe ndent increase in plasma corticosterone level, which could be blocked by pretreatment with CRF antiserum. CGRP injected into the lateral bra in ventricle increased the grooming and rearing activity and decreased the locomotor activity in an open field. On pretreatment with CRF ant iserum, the action of CGRP on grooming was blocked, while the action o n locomotion and rearing activity was unchanged. The results suggest t hat the CORP-induced action on pituitary-adrenal activation is mediate d by CRF. The action of CGRP on grooming in an open field is related t o the pituitary-adrenal activation, and either CRF or adrenocorticotro pic hormone or both may be involved in mediating the action of CGRP. T he action of CORP on rearing and locomotion is not affected by CRF ant iserum, indicating that the two behavioral actions are regulated by di fferent mechanisms.