Cimetidine prevents reduction in gastric mucosal blood flow during shock.

This study evaluated Cimetidine's possible role in regulating gastric mucosal blood flow in the anesthetized, stressed miniature swine. Stress consisted of hemorrhagic shock to a mean arterial pressure of 50 mm Hg. Twenty-one animals were divided into three experimental groups: untreated controls, preshock Cimetidine treatment group, and postshock Cimetidine treatment group. Gastric mucosal blood flows were determined (microsphere method) during a stabilization period and after 90 minutes of shock. Central hemodynamic indices were monitored throughout each experiment. In the fundus, mucosal blood flow decreased 59% in the controls, 11% in the preshock, and 28% in the postshock Cimetidine groups. Antral mucosal blood flow decreased 57% in controls, 19% in the preshock, and 33% in the postshock Cimetidine groups. In the corpal mucosa, blood flow decreased 53% in controls, 11% in the preshock group, and 41% in the postshock Cimetidine group. Cimetidine administration, both before and after shock, conferred significant protection on mucosal blood flow changes related to shock. Preshock drug administration had a significantly greater protective effect than postshock treatment on blood flow in the corpal mucosa.