Complement-dependent histamine release from rat peritoneal mast cells, induced by lipopolysaccharides from Bacteroides oralis, Fusobacterium nucleatum and Veillonella parvula.

The capacity of phenol/water extracted lipopolysaccharides (LPS) from Bacteroides, Fusobacterium and Veillonella to induce histamine release from rat peritoneal mast cells has been evaluated by means of a bioassay using atropinized guinea pig ileum and a fluorescence assay. Histamine release was found to be completely complement dependent. It was also found that LPS of Veillonella have the greatest capacity to induce histamine release and Bacteroides have the weakest.