Effect of Epinephrine, Antihistaminics and Adrenergic Blockade on Egg White Edema in Adrenal Insufficient Rats.

Abstract
Summary Epinephrine protects adrenal insufficient rats from the edema and mortality caused by the intraperitoneal administration of egg white. Mortality is prevented by doses (0.04 mg/kg) which are not able to prevent edema in rats with intact adrenals. The antihistaminic Phenergan, N-dimethyl-amino-2-propyl-l-thiodiphenylamine (“3277 RP”), in doses as low as 5 mg/kg prevent death from egg white edema in adrenalectomized rats. “SY-28”, N-(2-bromoethyl)-1-naphthalene-methylamine hydrobromide, a Dibenamine congener possessing both antihistaminic and adrenergic blocking activity, also prevents the edema and death, but is in itself toxic to adrenalectomized rats. “SKF-501”, N-(9-fluorenyl)-N-ethyl-β-chloroethylamine, a Dibenamine cogener with potent adrenergic blocking powers but with a low toxicity and without antihistamine action, also inhibits the edema and decreases the mortality. The possible modes of action are discussed.