THE RELATION OF COCAINE AND OF PROCAINE TO THE SYMPATHETIC SYSTEM

¹ From the Department of Pharmacology, Oxford, England

1. Cocaine, injected intravenously, dilates the denervated pupil even more than the normal; cocaine is without action on the denervated pupil only when applied to the eye externally.

2. The actions of cocaine can be regarded as sympathomimetic; though cocaine has also a direct stimulant action on smooth muscle and a toxic action on the heart which masks the sympathomimetic action.

3. Procaine is a sympathomimetic substance. It dilates the normal and the denervated cats pupil; it amplifies the contractions of the isolated auricles; it inhibits the isolated intestine. Like ephedrine and cocaine it augments the action of adrenaline in vivo, and abolishes the action of adrenaline in isolated tissues.

4. Procaine augments the pressor action of tyramine.

5. Cocaine and procaine depress the action of nicotine and of acetylcholine (after injection of atropine) upon the sympathetic ganglia.