ON THE ACTION OF PROSTIGMINE ON THE CIRCULATORY SYSTEM

¹ From the Department of Pharmacology, Harvard Medical School

The actions of prostigmine on the circulatory system have been studied on the heart-lung preparation of the dog, on the isolated frog heart, and on the cat.

Of these actions, the following are referable to the inhibition of cholinesterase: the actions on the heart rate, stroke volume, total output, and coronary flow of the heart-lung preparation of the dog; the increased response to vagal stimulation, the slowing of the heart rate, the drop in blood pressure, and the more pronounced effect upon the blood pressure following injection of acetylcholine in the cat.

The action of prostigmine on the isolated frog heart and the increase in blood pressure in the cat usually produced by the first injection of prostigmine and always produced after atropine are not explained by the inhibition of cholinesterase.