the characteristic insensitivity of sensory nerve endings to chemically induced pain brought about by capsaicin could be reproduced on the rat 's eye by pungent vanillylamides , homovanilloyl-alkylamides and piperine , while homovanilloyl-cycloalkylamides , -azacycloalkylamides , - alkylesters , -alkyl-homovanillylamides , undecenoyl-3-aminopropranololand zingerone were practically ineffective in this respect .
C0030193
pain
C0006931
capsaicin