Increased angiogenesis during wound healing in rats with streptozotocin-diabetes.

The neovascularization that occurs during wound healing in the perforated mesenteric membrane was quantitatively studied in rats with streptozotocin induced diabetes. The virtually avascular mesenteric windows in both controls and diabetic rats were perforated with a scalpel during laparatomy. At designated intervals during days 1-63 postoperatively, the mesenteries were excised, fixed, and cut perpendicularly through the wound margin or the central part of a closed wound. An unperforated window from each animal served as an internal control. The numerical microvascular density of the healing tissue and the unperforated control mesentery was assessed by morphometry on photomicrographs with regard to number of vascular profiles per mm length of mesentery or mm2 sectioned tissue area. The vascularity in unperforated windows of both diabetics and age-matched healthy controls was unaffected by laparotomy whereas perforation significantly increased the numerical microvascular density of the mesentery. The onset of angiogenesis in the perforated mesenteries occurred on days 5-7 and in both diabetics and controls, wound areas retained an increased numerical microvascular density throughout the observation period. The numerical microvascular density of the wound areas was greater in diabetics than controls following closure of the wounds. A number of wounds healed without being vascularized. The number of vascularized wounds was significantly higher in diabetic animals than controls.