Abstract
It has been reported that Tween 20, one of the nonionic surfactants, liberates tissue histamine (1-3), and that various surfactants are locally irritating at the conjunctival (4), intramuscular (5), percutaneous (6) and intracutaneous (7) sites of application. Therefore, the irritating effect is possible due partially to the histamine liberation. However, the increased capillary permeability by the intracutaneous injection of nonionic surfactants differed somewhat in mode of action from that caused by the same procedure of histamine (7-9). Especially, the increased capillary permeability by the procedure of polyoxyethylene monolauryl ether (a nonionic surfactant) is scarcely influenced by the repeated pretreatment of the animal with Tween 20 or by the previous administration of the antihistamine (10). These evidences led the present authors to conclude that the increased capillary permeability induced by the nonionic surfactants did not derive from the histamine liberation alone. The present study deals with the effects of the antihistamine, inorganic salts, a fatty solvent and cholesterol feeding on the increased capillary permeability induced by the intracutaneous injection of the nonionic surfactants in the rabbits.
