Enhancement of the anaphylactoid reaction in rats by salicylates.

Low doses of sodium or copper salicylate, administered at the same time as agents producing the anaphylactoid reaction in rats, significantly enhanced the onset, height and duration of the responses. The enhancement occurred after intraperitoneal or local administration. Enhanced transport of the high molecular weight agents into the bloodstream is suggested. However, the salicylates did not enhance histamine release from isolated peritoneal mast cells of rats induced by dextran and phosphatidyl serine.