The effects of local hyperthermia on the morphology of the small bowel

Intestinal lesions were produced experimentally by heating the eventrated loop of the small intestine of Wistar rats in 44 degrees C 0.9% saline 20 minutes. Luminal haemorrhage and elevation of the potassium concentration in the wash-out fluid were registered from the fifth minute of the experiment. In the sediment of the wash-out fluid erythrocytes, degenerated and necrotic epithelial cell clusters were found. Histologically the mildest lesions were subnuclear vacuolization of the epithelial cells and stromal oedema of the villi. In the medium-degree lesion subepithelial cleft formation, desquamation of the epithelial cells and denudation of the villi occurred. The fully developed lesion was characterized by the destruction of the villi intestinalis and haemorrhage. This lesion produced by local heating differs from the intestinal lesions of the rats exposed to high environmental temperature basically in the haemorrhagical nature of the former lesion.