STUDIES ON VERATRUM ALKALOIDS. XV. THE QUININE-LIKE EFFECT OF VERATRAMINE UPON THE SINGLE TWITCH AND UPON THE "VERATRINE RESPONSE" OF THE SARTORIUS MUSCLE OF THE FROG

¹ Department of Pharmacology, Harvard Medical School, Boston, Massachusetts

The secondary veratrum alkamine, veratramine, has an action upon the response of the isolated sartorius muscle of the frog to electrical stimulation, which is qualitatively and quantitatively very similar to the well known action of quinine. Veratramine increases the height of the single twitch in concentrations (w/v) of 1:300,000 to 1:100,000. In concentrations of 1:30,000 and 1:10,000, the increase in twitch height is transient; the twitch diecreases progressively and eventually the muscle no longer responds to the electrical stimulus. The "veratrine response", caused by veratridine 1:10 million or 1:5 million, is antagonized by veratramine 1:100,000, and the normal twitch is restored in a large percentage of the experiments.

Attention is drawn to other substances which—like quinine, quinidine and veratramine—are capable of antagonizing the "veratrine response", for example, the cardiac glycosides, ouabain and! digoxin, and the ergot alkaloid, dihydroergotamine.