Stimulation of wound healing in connective tissue : An experimental study using the perforated rat mesentery

Sammanfattning: Different aspects of wound healing in connective tissue were studied in the perloratedrat- mesentery model after mast cell activation and treatment with epidermal growth factor (EGF). This wound model is considered to reflect pure connective tissue repair.Standardized perforations were made with a scalpel in the centre of mesenteric windows and the various treatments were given as intraperitoneal injections.Mast cells were shown to be activated by laparotomy and perforation, as assessed by release of histamine. Preoperative pharmacological activation of mast cells, induced by Compound 48/80, significantly improved healing of mesenteric perforations. Activation prior to surgery resulted in superior healing compared with such activation postoperatively. Administration of a long acting histamine H2-receptor antagonist after mast cell activation did not affect healing.EGF-treatment significantly accelerated the healing of mesenteric perforations, increased the formation of healing tissue, and was found to be a mitogen in wounded by not in unwounded connective tissue. Sialoadenectomy, which reduces endogenous production ofEGF, did not influence healing. A model for morphometrical quantification of new blood vessel growth in the rat mesentery during connective tissue repair wasdeveloped. EGF-treatment did not significantly affect angiogenesis as shown by this technique.The results show that stimulation of wound healing in the perforated rat mesentery can be accomplished by preoperative mast cell activation and treatment with EGF. Various cellular events are influenced by such treatments, but the precise cellular mechanisms governing this stimulation remain to be shown.