The emetic action of strophanthidin in cats with denervated hearts.

Abstract

Strophanthidin is a cleavage product derived by hydrolising hispidus or Kombé strophanthin. It can also be obtained from cymarin, an active principle of Apocynum cannabinnum. 1 Its empirical formula, 2 as lately established, is C₂₃H₃₂O₆, 1/2 H₂O. Jacobs and Collins have, moreover, thrown much light upon its structural makeup. 3 Pharmacologically, strophanthidin has been but little studied.

As we have already pointed out, 4 this substance has marked emetic properties. It also acts upon the heart in a manner essentially like that of the strophanthins from which it is derived, when given in suitable doses.

Since strophanthidin is either quite rapidly eliminated from, or destroyed in, the animal body, its emetic action can be advantagiously observed repeatedly on the same individual animal. For this purpose, we have used cats (and a few dogs). We have found that emesis occurs promptly after any of the usual modes of injection (except, perhaps, by mouth), but we have employed the intraperitoneal route for the most part, confirming the results by intravenous injections. The average intraperitoneal dose is 0.20 mg. per kg.

The research here reported deals mainly with emesis in cats with partially and completely denervated hearts, though we have previously tested the substance on a large number (more than sixty) of normal cats. The operations performed and the number of animals used were as follows: 13 bilateral stellate ganglion excisions; 7 unilateral vagotomies, 2 double vagotomies; 12 double vagotomies with bilateral stellate ganglion excisions (extrapleural method); 9 bilateral vagotomies with bilateral (intrathoracic) stellate ganglion excision, together with removal of most of the thoracic sympathetic chain; 5 additional operations of this sort, with removal of the middle cervical ganglia also, thus insuring absolute denervation of the heart; 3 spinal cord sections at level of 7th vertebra; 3 decerebrations.