Differential reactivity of isolated mast cells from the rat and guinea pig.

The effects of various chemical histamine liberators on isolated rat peritoneal, rat mesenteric and guinea-pig mesenteric mast cells were examined. All three cell types responded, but to different degrees, to calcium ionophores and surface active agents. The rat mesenteric cells also reponded, but less effectively than the peritoneal cells, to compound 48/80, peptide 401 from bee venom and ATP. Rat mesenteric cells were essentially refractory to the action of dextran and guinea-pig cells were almost totally unresponsive to the named secretagogues. These results show that there are marked functional differences between the mast cells examined and suggest that isolated tissue cells may usefuly complement rat peritoneal cells in the study of anaphylactic and anaphylactoid reactions.