Gastromucosal lesions in rabbits with chronic schistosomiasis.

Upper gastrointestinal hemorrhage is one of the most important complications in portal hypertension secondary to schistosomiasis. Esophageal varices and gastric mucosal lesions are additional sources of bleeding. We studied the histologic and ultrastructural features of gastric mucosa in rabbits with chronic schistosomiasis (n = 10), with normal animals (n = 10) as controls. Our results confirm that in schistosomiasis, the gastric mucosa has characteristic functional and morphological features that may predispose it to the various damaging factors. Mucosal specimens reveal dilated submucosal vein with submucosal edema, ectasia of mucosal capillaries and venules. The mucosal vessels have conspicuous endothelial cells with prominent cytoplasm and numerous tiny projections extending into the vessel lumen. The submucosal venules show morphologic feature of arterialization. There are increased submucosal arteriovenous communications with a reduction in the effective mucosal blood flow. In addition, there are a number of eggs seen in the gastric mucosa of the rabbits with schistosomiasis. The granuloma may cause structural damage to the gastric mucosa. This finding suggests that schistosomiasis may play an important role in gastric lesions.