REDUCTION OF SURGERY INDUCED PERITONEAL ADHESIONS BY METHYLENE-BLUE

BACKGROUND: The possible involvement of inflammatory mediators such as nitric oxide (NO), and reports of protective effects of antioxidants, led us to test the effectiveness of methylene blue and NO synthesis i nhibitor in reducing adhesion formation. METHODS: Generation of adhesi ons in rats, by scraping the anterior uterine horn wall, was followed by intraperitoneal administration of saline, methylene blue, or N alph a-t-BOC-omega-nitro-L-arginine. Additional rats received identical tre atments, but without the serosal damage, Two weeks later, formation of adhesions was quantitatively graded. RESULTS: Adhesions were found in <5% of the rats with the sham surgery, regardless of treatment. In th e experimental group, >95% of the rats treated with saline or NO synth etase inhibitor had severe adhesions, in contrast to 5% of the methyle ne blue treated rats. Severity of adhesion was lower in the methylene blue group (P <0.001). CONCLUSIONS: Methylene blue was very effective in preventing formation of peritoneal adhesions. Its activity is proba bly through inhibition of free-radical generation and not of nitric ox ide action. (C) 1998 by Excerpta Medica, Inc.