The Histamine-Heparin Complex

Some factors concerned in the formation in vitro of a complex between the base histamine and the acid heparin have been studied. More histamine is contained in the complex when precipitation is carried out in acid medium in the presence of adenosine triphosphate. Although the staining properties and morphological characters of the complex resemble those of natural mast cell granules, it has not been possible to release most of the histamine from the synthetic granules without dissolving them. 5-Hydroxytryptamine, noradrenaline and adrenaline failed to form complexes with heparin and did not alter the formation of the complex of histamine and heparin.