Changes in the intracellular calcium ion concentration in the gastric mucosa in a rat ischemia-reperfusion model

To investigate the role of the intracellular calcium ion in the development of acute gastric mucosal lesions, phosphorylase a activity was measured as an index of the intracellular calcium ion concentration ([Ca2+]i), using Lowry's method, in the rat ischemia-reperfusion model. [Ca2+]i increased significantly at the end of the ischemic state without acute mucosal lesions (AGML). After reinfusion, [Ca2+]i showed a slight increase and AGML developed. Continual intravenous infusion of the calcium channel blocker, diltiazem (1 mg/kg/hr), inhibited the increase in [Ca2+]i in the ischemic state and reduced the development of AGML after reinfusion. These results suggest that the increase in [Ca2+]i in the ischemic state plays an important role in the development of AGML.