Studies on Cryptolepine

Abstract

The inhibitory effects of cryptolepine and its interaction with prostaglandin E (2), indomethacin, adrenaline and acetylcholine have been investigated on the isolated rabbit duodenum. Cryptolepine (10-20 microg ml (-1)) or adrenaline (0.5-1 microg ml (-1)) or indomethacin (10-20 microg ml (-1)) abolished or reduced pendular contractions and relaxed the tissue. Cryptolepine (20 microg ml (-1)) produced an initial contraction before relaxation of the tissue. Cryptolepine (10-20 microg ml (-1)) abolished responses of the duodenum to added prostaglandin E (2) and acetylcholine, but failed to reduce prostaglandin production. The results suggested that cryptolepine antagonises prostaglandin, but has no inhibitory effect on its synthesis or release.