Secretory activity of mast cells in the presence of cholinergic agonists

Abstract

Mast cells from rat peritoneal fluid were studied under cholinergic stimulus.The cells were purified by a continuous Ficoll gradient and were challenged with acetylcholine and carbamylcholine.The preparations showed the typical dose-response pattern against compound 48/80 with a dose interval of 0.5-1 microM that clearly increased the secretion.However, the histamine release elicited by increasing concentrations of acetylcholine and carbamylcholine was of little magnitude and similar for all the concentrations; this kind of response has not a dose-response profile and does not appear to be explained by the presence of a cholinergic receptor on the mast cell cellular membranes.The cholinergic agents neither stimulated directly the mast cells nor did they cause any variation in the 48/80 response.The histamine release pattern obtained with these agents cannot support the hypothesis of a primary cholinergic receptor on mast cells.However, if such receptor existed, its action could only be of secondary importance, and in fact such action was not manifested with the compound 48/80.