Histamine secretion from mast cells stimulated with sodium orthovanadate

Sodium orthovanadate was found to be an effective histamine liberator from peritoneal mast cells of the rat and mouse. The release process was slow, non-cytotoxic and strongly dependent on pH and extracellular calcium. The effect was highly tissue and species specific and human basophil leucocytes and tissue mast cells of the rat and guinea pig were only weakly responsive or essentially unreactive.