The effect of cyproheptadine on the release of corticotrophin releasing factor.

The effect of cyproheptadine was tested on the neurotransmitter-induced release of corticotrophin releasing factor (CRF) from the rat hypothalamus in vitro. It was found that cyproheptadine inhibited both acetylcholine and 5-hydroxytryptamine-induced release of CRF. Cyproheptadine did not interfere with the ACTH releasing ability of CRF. These results suggest that cyproheptadine reduces the high circulating levels of ACTH in some patients suffering from Cushing's disease and Nelson's syndrome by inhibiting CRF secretion.