Interactions of bradykinin, prostaglandin E1, 5-hydroxytryptamine, histamine and adenosine-5′-triphosphate on the dye leakage response in rat skin

Dye leakage in rats produced by intracutaneous injections of irritants was quantitated using an azovan blue technique. Concentration-response lines were obtained for irritants alone and in presence of constant concentrations of other irritants. 5-Hydroxytryptamine (5-HT) (10-7M) potentiated histamine, bradykinin and prostaglandin E1 (PGE1) but inhibited adenosine-5'-triphosphate (ATP). Histamine (10-5M) potentiated bradykinin, PGE1 and ATP. Bradykinin (10-6M) potentiated PGE1 only, but PGE1 (10-6M) potentiated bradykinin, 5-HT and histamine. ATP (10-4M) potentiated 5-HT, histamine and PGE1. Release of ATP during stimulation of sensory nerves might explain enhanced neurogenic oedema observed in skin surrounding an area pretreated with compound 48/80.