Veratramine, an Antagonist to the Cardioaccelerator Action of Epinephrine.

Abstract

The Veratrum alkaloid veratramine abolishes or prevents the cardioaccelerator action of epinephrine in the heart-lung prepn. of the dog and in the spinal and pithed cat. It does not abolish the positive inotropic cardiac action nor the vasopressor action of epinephrine. Exclusion of vagal mechanisms by large doses of atropine is without influence. The veratramine effect is long lasting in the isolated heart; it wears off at a measurable rate in the spinal cat; it can be overcome, at least partially, by high concns. of epinephrine.