Microcirculatory disturbances in gastric mucosa during ulcer disease and effects of serotonin on their dynamics.

Experiments on rat model of stress-induced gastric ulcers revealed marked circulatory disturbances in ulcerated gastric mucosa associated with arteriolar spasm and venous congestion and leading to perivascular edema, diapedesis of erythrocytes, and microhemorrhages. These changes were most pronounced on day 1 after ulcer modeling and progressively decreased during healing (day 14-21). On day 3, arterial hyperemia developed against the background of venous congestion, which was probably related to progressive repair.