THE ACTION OF AN ALKALOIDAL PRODUCT FROM THE LEAF OF SOLANUM PSEUDOCAPSICUM, L

¹ From the Pharmacological Laboratory, University of the Witwatersrand, Johannesburg and the Cardiological Department, Johannesburg General Hospital

1. The alkaloidal product from the leaf of Solanum pseudocapsicum, L. has some toxicity and the minimum lethal doses for the frog, rabbit and cat are given.

2. The most marked effect is on the heart which is slowed by direct action on the muscle. Impulse formation at the pacemaker is slowed and there is marked retardation of conduction throughout the cardiac tissues. These effects are produced independently of the vagus. Larger and toxic doses cause ventricular fibrillation.

3. The substance produces insignificant effects on smooth muscle.

4. The main action, viz., on the heart, is the same as that produced by a dry alcoholic extract of the leaf.