Histamine release by free radicals: paracetamol-induced histamine release from rat peritoneal mast cells after in vitro activation by monooxygenase.

The incubation of paracetamol with isolated rat serosal mast cells evokes the release of histamine only in the presence of (S10) liver microsomes obtained from PCB or phenobarbital treated rats. The release of histamine was not accompanied by a leakage of lactate dehydrogenase and was blocked by the antioxidant alpha-tocopherol and by D-mannitol, an hydroxyl free radicals scavenger. The data are consistent with the metabolic oxidation of paracetamol in the generation of reactive intermediates capable of activating the sequential exocytosis.