The Mechanism of the Hypotensive Action of Veratrum Alkaloids.

Abstract
Germitrine and neogermitrine, as well as other Veratrum alkaloids, produce reflex respiratory and circulatory effects in dogs. In major par these responses are initiated by stimulation of afferent fibers which run in the vagi-aortic nerves. In addition, all clinically active Veratrum alkaloids produce a reversible blockade of the carotid sinus pressor reflex. Activity upon this particular reflex corresponds approx. to the reported therapeutic action of these agents in hypertension. It is suggested that this activity may be made the basis of bioassay procedures for this group of substances. Results were suggestive that an important action of the Veratrum alkaloids may be directly on the vasomotor center. In excessive dosage germitrine and neogermitrine produce a rise in blood pressure rather than a fall.