COMPARATIVE ANTIEDEMIC EFFICIENCY OF EPI- NEPHRINE AND RELATED AMINES AND PITUI- TARY IN EXPERIMENTAL EDEMAS

In a previous paper (1), it was shown that epinephrmne can pre-vent, directly and also indirectly, the severe edema of para-phenylenediamine ’ in rabbits and cats. The direct antiedemic action was demonstrated with continuous intravenous injections of epinephrine, and the indirect, with repeated hypodermic ad-ministrations of nicotine, picrotoxin and strychnine, provided these latter alkaloids caused an adequate increase in epinephrmne output of the adrenals. These results established the experimen-tal basis of the reputed benefits from epinephrine in clinical edemas, namely, vasoconstriction and diminished availability of plasma for edema formation. However, the chief disadvan-tage of epinephrmne is its fleeting action, both experimentally and clinically. Of the drugs which act indirectly by increasing the epinephrmne output more or less continuously, only strychnine might be feasible therapeutically, but there are other drugs, re-lated to epinephrine chemically or pharmacologically, or both, which appear to be less toxic than strychnine and to possess ad-vantages over epinephrmne. These are tyramine, ephedrine, phenylethanolamine and pituitary extract. A priori, the merits of these latter drugs as possible antiedemic agents would appear to be as follows: Ephedrine and tyramine cause a sustained vasoconstriction and are effective on oral ad-ministration. Phenylethanolamine, according to a recent study I Hereafter, throughout the paper, the abbreviation “para ” is used in place of the long “paraphenylenediamine hydrochloride.