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 aminopropanol and zingerone were practically ineffective in this respect. Desensitizing potency was not parallel with the stimulating effect of the compounds, e.g. the strongly pungent homovanilloyl octylester failed to desensitize the receptors, while the less pungent homovanilloyl dodecylamide proved to be a more potent desensitizing agent than capsaicin itself. It is concluded that the inverse position of the acylamide linkage does not modify, while its replacement by an esteric group completely abolishes the desensitizing activity. In contrast to the stimulating effect, in desensitizing action the presence of an alkyl chain is essential and its optimal length corresponds to 10-20 C atoms. On the basis of these results the possible molecular interactions at the site of action are discussed.
|Number of pages||5|
|Publication status||Published - Dec 1 1976|
ASJC Scopus subject areas
- Drug Discovery