Morphological studies of the rat small intestine after jejuno-ileal transposition.

The small intestine of the rat was studied by light, fluorescence, transmission electron and scanning electron microscopy after jejuno-ileal transposition. No systematic cell damage in the wall layers of the transposed intestine was observed. Two and 12 weeks postoperatively the villi of the transposed ileum were significantly higher than in the ileum of both sham-operated animals and intact controls. In corresponding comparisons the transposed jejunum also exhibited slightly higher villi 2 weeks postoperatively, but this difference had decreased 10 weeks later. The length and breadth of the villi appeared to be less affected by the operation. In comparison with corresponding sham-operated and intact animals the epithelial cells along the villi in the transposed ileum were initially increased in number per mm basement membrane, but later decreased.