Portal hypertension and gastric lesions in the rat.

Gastric lesions occurred spontaneously and were increased in number by seven hours of restraint stress in rats with portal vein constriction (PVC). Vagotomy and pyloroplasty protected the congested stomach from erosion formation with stress. Major weight loss occurred two days after PVC, but not thereafter. Platelet counts were decreased in intact and splenectomized rats with portal hypertension, but prothrombin time, partial thromboplastin time, and fibrinogen were unaffected, and histological stains failed to demonstrate thrombin in the gastric blood vessels. The oxygen pressure (PO2) of the gastric luminal fluid was decreased at day 2, but was normal at day 4 after PVC. Hypersection of acid and abnormal acid equilibration were not observed in the stomach. Gastric congestion, weight loss, and possibly portasystemic shunting of blood contributed to the higher incidence of gastric erosions with portal hypertension.