Metronidazole and wound healing

Metronidazole, an antibiotic, has enjoyed success as a therapeutic agent in the treatment of inflammatory bowel disease (I.B.D.). Surgical management of I.B.D. is not uncommon and involves resection of diseased portions of gastrointestinal tract with subsequent anastomoses. The object of this study was to assess the effect of metronidazole in situations where the colonic anastomoses involve: i) non-inflamed apposing segments, and ii) two segments experiencing an acute, non-specific inflammatory reaction. Surgery, consisting of division of the descending colon which was then anastomosed, was performed on male Sprague-Dawley rats. At 1, 3 and 7 days following surgery the bursting pressure of the anastomoses was tested and tissue samples were taken for hydroxyproline content assay. In non-experimentally inflamed anastomotic tissue, metronidazole-treated animals exhibited a significant increase in bursting pressure on days 1 and 3 over control animals. By the 7th day following surgery the gap had narrowed to a non-significant difference. The pattern was reversed in anastomoses of experimentally inflamed tissue. Metronidazole-treated animals had bursting pressures which were significantly lower than controls at all three sampling intervals. There appeared to be no direct correlation between collagen concentration at wound site and its strength as assessed by bursting pressure. In all groups however, the collagen concentration at the wound site rose steadily with increased time following surgery.