Comparison of histamine and 5-hydroxytryptamine content and secretion in rat mast cells isolated from different anatomical locations.

Rat mast cells, isolated from different anatomical locations, were found to exhibit heterogeneity with respect to histamine and 5-hydroxytryptamine (5-HT) content. Unlike peritoneal mast cells, those derived by enzymatic digestion of rat lung and mesentery tissues contained amounts of 5-HT in excess of histamine. Both compound 48/80 and A23187 were more effective liberators of histamine than 5-HT in each cell type, despite their differences in relative amine content. However, in response to a mixture of specific antigen and phosphatidylserine, the pattern of secretion of both amines from each mast cell type was observed to be essentially colinear. These results are discussed in terms of amine release mechanisms and post-secretory events.