STUDIES ON VERATRUM ALKALOIDS

XII. A Quantitative Comparison of the Antiaccelerator Cardiac Action of Veratramine, Veratrosine, Jervine and Pseudojervine

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

1 . The antagonistic action of veratramine and jervine and of their respective glycosides, veratrosine and pseudojervine, has been studied quantitatively in the heart-lung preparation of the dog using continuous infusion of l-epinephrine under standard conditions to increase heart rate.

2. When l-epinephrine base is infused at the rate of 3 microgm. per minute the dose causing 50 per cent inhibition of acceleration (I₅₀) is 0.16 mgm. veratramine and 7.6 mgm. jervine. Jervine has only 2 per cent of the antiaccelerator potency of veratramine. The glycosides veratrosine and pseudojervine have the same order of potency as their respective aglycones. The I₅₀ of veratrosine is approximately 0.1 mgm.

3. The term "antiaccelerator" is introduced to denote a specific and selective antagonistic action to the positive chronotropic effect of epinephrine and of substances acting like it upon the pacemaker tissue of the heart.

4. In the heart-lung preparation of the dog there is a great variability of initial rate and of acceleration achieved by continuous infusion of epinephrine under standard conditions. Nevertheless, the percentage inhibition of acceleration caused by the antiaccelerator action of the secondary veratrum alkamines is relatively uniform.

This article has been cited by other articles:

				S. Margolin, G. Lu, J. Yelnosky, and A. Makovsky Antiaccelerator and Antiarrhythmic Cardiac Action of Synthetic Steroid Alkamines Science, October 8, 1954; 120(3119): 576 - 577. [PDF]