Background: The purpose of the study was to examine the microscopic changes of intestine villus and ultrastructural changes of tight junction in the presence of intra-abdominal hypertension (IAH) of 20 mmHg.
Materials and methods: Forty Sprague-Daley rats (250 +/- 25 g) divided into four groups (n = 10) were studied. In 30 animals, the intra-abdominal pressure was increased to 20 mmHg for 1 hr, 2 hr, and 4 hr, respectively. The others served as controls. The specimens of the intestines were submitted to histopathology using hematoxylin and eosin staining, and to ultrastructural analysis using a scanning electron microscope.
Results: The histopathological study revealed different degrees of changes ranging from swelling and degeneration of villous epithelial cells to extensive denudation and collapse of the villus. Ultrastructural analysis revealed dilatation of the tight junctions and paracellular spaces in the presence of IAH. The severity of the damage was related to the time of IAH.
Conclusions: Increased IAH caused a significant damage to the intestinal epithelium and a marked dilatation of intestinal tight junction, leading to the increased mucosal barrier permeability. It may explain why IAH was often associated with bacterial translocation and sepsis.