Action of Histamine on Procaine Nerve Block

Abstract

IN a communication in Nature of October 22, 1949, Bárány and Nordquist¹ reported certain observations on the action of histamine on nerve block caused by procaine and pyribenzamine. They were led to perform these experiments because histamine has been found in nerves^2,3, because most antihistaminic drugs are local anæsthetics, and because it has been shown that the local anæsthetic procaine also has an antihistaminic action^4,5. Bárány and Nordquist found that, using the gastrocnemius muscle as an index of conduction in the frog sciatic nerve, histamine antagonized the local anæsthetic action of procaine and pyribenzamine. But it must be remarked that the concentration of histamine used, 0.4–0.6 per cent histamine dihydrochloride, was very large and unlikely to be encountered under physiological conditions.