[Lipoxygenase inhibitors and mast cell degranulation].

Lipoxygenase inhibitors block the release of histamine from protaminesulfate-stimulated peritoneal mast cells of the rat in vitro. The order of this inhibitory activity of the agents does not correlate with the order of this inhibitory activity of the agents does not correlate with the order of their inhibitory activity against lipoxygenases from reticulocytes and peas. Antioxidants/radical scavengers, which do not inhibit lipoxygenase activity (mannitol, hydrochinone) block the protaminesulfate-activated degranulation of peritoneal rat mast cells, too. Therefore we assume that activated oxygen radicals are generated by stimulation of pRMZ with protaminesulfate. These oxygen radicals could be promotors for the histamine secretion of the peritoneal mast cells. Consequently, lipoxygenase inhibitors with radical scavenging properties may influence degranulation of peritoneal mast cells of the rat by two mechanisms, namely by reduction of the synthesis of 5-LOX-products (promotors of the histamine release) and by reduction of the toxic effects of activated oxygen radicals.