STUDIES ON PEROXISOMES OF COLONIC MUCOSA IN CROHNS-DISEASE

The etiology and pathogenesis of Crohn's disease, a chronic inflammato ry bowel pathology, have not been elucidated yet. In particular, the b ehavior of peroxisomes in inflamed colonic mucosa has not been investi gated despite their important role in cellular oxidative metabolism. U sing cytochemistry at the ultrastructural level, we have observed thes e catalase-positive organelles. In addition, biochemical analyses have revealed the specific activities of catalase and cyanide-insensitive acyl-CoA oxidase. Mucosal biopsy specimens from inflamed and noninflam ed areas of Crohn's patients were compared to control biopsies. We fou nd that Crohn's disease was marked by an important diminution in the p eroxisomal frequency per cell unit area. If catalase activity was not affected by this pathology, cyanide-insensitive acyl-CoA oxidase, an e nzyme of the peroxisomal p-oxidation system, was found diminished in i nflamed and in noninflamed areas. In conclusion, our results showed th at Crohn's disease is accompanied by peroxisomal modifications but the number and the enzyme activities of colonic peroxisomes are less deep ly altered in Crohn's disease than during neoplasia. This fact suggest s that a relation may exist between the degree of peroxisomal deficien cy and the clinical severity of colonic disease.