THE ACTION OF PROCAINE AND OF COCAINE ON MAMMALIAN SKELETAL MUSCLE

¹ From the Department of Pharmacology, Oxford, England

1. Cocaine and procaine have a curare-like action upon normal mammalian skeletal muscle.

2. This action is not identical with that of curare since it is still exerted in fully curarised muscle and after complete degeneration of the motor nerves.

3. Cocaine and procaine have a much greater action in partially curarised than in normal muscle.

4. Cocaine and procaine antagonise the action of acetylcholine and of nicotine in denervated muscle.

5. It is suggested that the action of cocaine and procaine is in part, a direct reduction of the contractility or excitability of the muscle fibres.

6. The individual variation in sensitivity to cocaine and procaine as measured by arrest of the heart by slow intravenous infusion, is very great.