Influence of urea-equivalent groups in position 5 of 2-amino, 2-(1-aminoethylidenamino) and 2-guanidino thiazole derivatives on H2-receptor antagonist activity in gastric fistula cat

Abstract

A series of thiazole derivatives, in which a side-chain with different urea-equivalent groups was introduced in position 5 of the heterocycle, have been tested as inhibitors of dimaprit-induced gastric acid and pepsin secretion in the gastric fistula cat. By comparing the in vivo and the previously reported in vitro activity of these compounds, we can note a very close parallelism not only in the quality of their action but also in the estimates of pA2 values. These data support an interdependence between the molecular substructures and the affinity for the H2-receptor.