Isolation of Mast Cell Degranulators from the Celomatic Fluid of Parascaris equorum

Two mast cell degranulating factors, which closely resemble proteins in their chemical-physical behavior, were isolated from the celomatic fluid of Parascaris equorum und highly purified by combinations of salting out, ion-exchange chromatography and isoelectrofocusing. Both factors proved to be positively charged molecules of molecular weight close to 3-4 × 104 which, in terms of molar concentration, were as efficient as compound 48/80 in selective induction of histamine release.