Biologically Active Principles Occurring on Histamine Release from Cat Paw, Guinea Pig Lung and Isolated Rat Mast Cells

Histamine release was induced from perfused cat paws and isolated rat mast cells with compound 48/80, and from sensitized guinea pig lungs with antigen. Concomitantly occurring biologically active substances were separated by various chromatographic procedures (silicic acid column, silicic acid impregnated paper, etc.). From all the species several spasmogenic principles were obtained. Chemical and biological properties in dicated the presence of unsaturated fatty acids, phosphatidyl and phosphatidal choline and an“SRS” principle. The“SRS” principles from the three species seemed to be identical or very closely related. Phosphatidase A‐like and chymotrypsin‐like enzymes are present in mast cells. Such enzymes are the only enzymes shown to be able to degranulate mast cells. The possible connection between these enzymes and the formation of spasmogenic principles during histamine release is discussed.