Proceedings of the 25th annual meeting From October 13–15, 1983—Yamaguchi, Japan

Although H~ receptor antagonist has a powerful anti-secretory effect, the role of this drug on the mucosal microcirculation remains unclear. In the present study, we investigated the effect of cimetidine and ranitidine on the gastric rnucosal hemodynamics and oxygen sufficiency in rats and human using reflectance spectrophotornetry. The intravenous administration of cirnetidine and ranitidine did not alter the mucosal blood volume and oxygen sufficiency at the basal state in rats. However, in face of hemorrhagic shock, these drugs significantly inhibited the decrease of rnucosal blood volume and maintained the oxygen sufficiency of the gastric rnucosa. The stress ulceration was also prohibited by administration of these drugs. Clinically, after H2 receptor antagonist treatment of intractable ulcer, the rnucosal blood volume at the ulcer margin increased markedly, and the ulcer healed within a few months. These results suggest that H2 receptor antagonist also acts on the gastric mucosal microcirculation and these dual effects may yield the excellent results.