The use of an in vitro binding assay to predict histamine H2-antagonist activity

Thirty-seven compounds were evaluated for their ability to inhibit histamine stimulated adenylate cyclase and to inhibit 3H-tiotidine binding. The compounds examined included a number of known H2-antagonists and a number of potential H2-antagonists of diverse chemical structure. The correlation between the Ki values from the binding assay and from the inhibition of adenylate cyclase was calculated to be r = 0.99, p less than 0.001. Thus 3H-tiotidine binding in guinea-pig cerebral cortex can be used to give a valid assessment of histamine H2-receptor activity.