STUDIES ON VERATRUM ALKALOIDS

V. THE EFFECT OF VERATRIDINE AND CEVINE UPON THE CIRCULATION IN ANESTHETIZED DOGS, WITH PARTICULAR REFERENCE TO FEMORAL ARTERIAL FLOW

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

1. Veratridine injected intravenously in dogs of 15 to 19.2 kgm. body weight in doses of from 0.02 to 0.14 mgm. produces an abrupt fall in blood pressure and heart rate, and respiratory inhibition, by way of reflexes mediated partly but not solely by afferent fibers in the vagus nerves.

2. The fall in blood pressure results partly from bradycardia and partly from a vasodilatation of the arterial tree as represented by the femoral arteries.

3. The peripheral dilatation is neurogenic and not the result of a direct action upon vascular smooth muscle. It is independent of the respiratory action.

4. Vagotomy almost completely eliminates the heart rate and respiratory effect of small doses of veratridine, and reduces, but does not abolish, the vasodilatation.

5. Large doses of veratridine (0.5 to 1.0 mgm.) cause, after vagotomy, an increase in blood pressure and heart rate, probably partly as a result of epinephrine liberation. The action of the epinephrine on the peripheral vessels masks a simultaneous decrease of vasoconstrictor tone.

6. Cevine lacks the characteristic depressor effect of veratridine in doses up to 2000 times the minimal effective dose of its veratric acid ester.

This article has been cited by other articles:

				D. H. Bergel and G. S. Makin Central and Peripheral Cardiovascular Changes Following Chemical Stimulation of the Surface of the Dog's Heart Cardiovasc Res, January 1, 1967; 1(1): 80 - 90. [Abstract] [PDF]

				G. K. Moe A Simple Technique for Continuous Registration of Blood Flow Science, April 15, 1949; 109(2833): 381 - 381. [PDF]