Vascular endothelium and smooth muscle remodeling accompanies hypertrophy of intestinal arterioles in streptozotocin diabetic rats.

The purpose of this study was to document alterations in endothelial and smooth muscle cell morphology of first- and second-order intestinal arterioles after 6 months of streptozotocin-induced diabetes. Both light and scanning electron microscopic techniques were used to quantitate the changes in the microvasculature. After rendering the first- and second-order intestinal arterioles passive and processing the vessels, it was determined that these microvessels were significantly dilated in the diabetic animals. Further examination revealed that in the diabetic animals, the cross-sectional area of the endothelial layer was increased in both 1A and 2A vessels, and the smooth muscle layer cross-sectional area was significantly increased in 1A vessels. Individual smooth muscle cells were significantly increased in width in the diabetic animals, but not in length. These data suggest that in this model of diabetes in rats, intestinal arteriolar hypertrophy was accompanied by significant remodeling of the arteriolar wall.