Pathology of passive mesenteric anaphylaxis in the chicken.

Passive mesenteric anaphylaxis (PMA) was produced on intravenous challenge by bovine serum albumin in chickens which had received two hours earlier an intraperitoneal injection of anti-BSA chicken serum. Sequential study of permeability and cellular responses, using colloidal carbon, revealed a biphasic pattern of increased permeability which was confined to venules and small veins only. The cell population comprised an infiltration of heterophils, monocytes and basophils. Marked degranulation and disruption of mast cells accompanied by a significant decrease in their number suggested their active participation. There was strong evidence that the activated mediator cells were both mast cells and basophils. It is suggested that PMA may offer an excellent experimental model in avian anaphylaxis research.