[Histamine reduction by means of oncolytically active and oncolytically non-active clostridial strains (author's...

Spores and vegetative forms of oncolytically active and oncolytically non-active clostridial strains were tested for histamine reducing activity (isolated ileum of guinea pig used for testing, waterbath method acc. to Magnus, Fig. 1). Culture media and the washed intact material did not show any or only very little effectiveness. On the other hand the fractionated, charges diminished histamine standard solutions except for very little remaining activity in the case of all strains. This effect was stronger in vegetative forms than in spores (Fig. 2). The histamine effect on the isolated organ was generally increased by means of culture media as well as by the washed intact material. In this respect, preparations of non-lytic strains showed a slightly higher effectiveness than preparations of lytic clostridial strains (Fig. 2). It was shown in earlier investigations (cf. bibliography) that the charges of clostridial strains decompose plasmakinin (synthetic bradykinin) at varying rates. Reduction of histamine activity by means of clostridia could lead to a decrease of the microcirculation and capillary-permeability in the tumor tissue (as hypothesized for bradykinin) and thereby favour its disintegration.