EVALUATION OF ANTAGONISTS OF HISTAMINE, 5‐HYDROXYTRYPTAMINE AND ACETYLCHOLINE IN THE GUINEA‐PIG

Abstract

Changes in the resistance to entry of air into the lungs of anaesthetized guinea‐pigs have been used to study the effects of histamine, 5‐hydroxytryptamine, and acetylcholine. Some known antagonists of these bronchoconstrictor agents have been investigated. The degree of antagonism has been expressed in terms of the dose ratio, previously used only with in vitro preparations.