THE ACTION OF THE ERYTHROPHLEUM ALKALOIDS UPON THE ISOLATED MAMMALIAN HEART

¹ From the Department of Pharmacology, Harvard Medical School, Boston

The cardiac action of the erythrophleum alkaloids, cassaine hydrochloride, nor-cassaidine hydrochloride, erythrophleine sulfate, and coumingine hydrochloride, was studied in the heart-lung preparation of the dog. All the alkaloids have a positive inotropic action which leads to an increase of the work of the heart, particularly in experimental heart failure. In large enough doses all the alkaloids lead to changes in heart rate and to irregularities of rhythm. Our data indicate that nor-cassaidine and cassaine have a larger ratio between the minimal irregularity dose and the minimal positive inotropic dose than coumingine.

Erythrophleic acid is devoid of any characteristic action upon the heart in a dose more than 100 times larger than the minimal positive inotropic dose of erythrophleine sulfate.