Inhibitory actions of enprofylline and aminophylline on extravasation of plasma proteins induced by various agents in the rat skin.

Increased plasma protein leakage induced by i.d. injections of histamine, 5-hydroxytryptamine, bradykinin, prostaglandin E2 and ionophore A23187 in the rat skin was inhibited non-specifically by enprofylline and aminophylline in a dose related manner. Depending on the agonist used, on a weight basis enprofylline was 2.9-6.6 times more potent than aminophylline when both were given i.p. and 1.4-2.2 times more active when administered orally. Inhibitory actions of enprofylline and aminophylline were unaffected by pretreatment of animals with phentolamine and propranolol, but reduced in adrenalectomized animals.