The release of histamine from rat mast cells by chymotrypsin

The release of histamine from rat peritoneal mast cells induced by alpha-chymotrypsin and that induced by antigen have characteristics in common. The kinetics of histamine release initiated by the two agents are similar. Both alpha-chymotrypsin and antigen release histamine in the absence of extracellular calcium, phosphatidyl serine enhances the release, and disodium cromoglycate inhibits both reactions. In contrast, extracellular alpha-chymotrypsin does not induce histamine release from cells isolated from fragments of human lung, human basophils, histamine-containing cells lavaged from the bronchial lumen of the rhesus monkey, fragments of human lung and fragments of guinea pig lung.