Mucosal Enzymes in Human Inflammatory Bowel Disease with Reference to Neutrophil Granulocytes as Mediators of Tissue Injury

Abstract

1. Biopsies of rectal mucosa were obtained for histology and enzyme analysis from 32 patients with inflammatory and functional bowel disorders, and the biopsies were classified morphologically as active colitis, quiescent colitis or normal. 2. Supernatant fractions of biopsy homogenates were assayed for their content of the proteolytic enzymes alpha-chymotrypsin, elastase and cathepsin D, and of protein, unsaturated vitamin B12-binding capacity, lysozyme, myeloperoxidase and N-acetyl-beta-glucosaminidase. 3. Mean unsaturated vitamin B12-binding capacity was significantly raised above normal in the active colitic mucosa, and mean lysozyme activity was raised above normal in both active and quiescent mucosae. 4. In active colitic mucosa there was no rise above normal in mean activities of any of the proteolytic enzymes, though a significant fall below normal occurred in mean N-acetyl-beta-glucosaminidase activity in the active colitic group.

Enzyme Activities in Biopsy Specimens from Large-Bowel Mucosa in Ulcerative Colitis

“…As found by others (19,20), decreased levels of Nacetyl-PD-ghcosaminidase were demonstrated in both active and quiescent ulcerative colitis, whereas we were unable to confirm decreased levels of acid pglucuronidase in active colitis, as previously found in the studies of Danovitch et al (21) and O'Morian et al (19). The activity of acid phosphatase was significantly reduced only in quiescent ulcerative colitis and not in active colitis.…”

Leucocyte Elastase in Chronic Inflammatory Bowel Diseases: A Marker of Inflammatory Activity?

“…Studies investigating concentrations of elas tase in the inflamed bowel mucosa might be more conclusive. Kane and Vincenti [24], however, using an assay of biological activity failed to show increased tissue levels of elas tase in inflammatory bowel disease. This could be explained by rapid binding of elas tase to its protease inhibitors, particularly to a r proteinase inhibitor.…”

“…This could be explained by rapid binding of elas tase to its protease inhibitors, particularly to a r proteinase inhibitor. The studies of Kane and Vincenti [24] should therefore be re peated, but now measuring the elastase ct|-proteinase inhibitor complex employing the method described by Neumann et al [17],…”

Increased Faecal Glycosidases in Patients with Crohn’s Disease

“…Granulocytes as well as mucosal epithelial cells are potential sources of tissue degrading enzymes. Lyso zyme, acid phosphatase and arylsulfatase ac tivities are all increased in inflamed mucosal cells of patients with colitis ulcerosa and Crohn's disease, but the activity of proteases, N-acetyl-P-glucosidase and p-glucuronidase was decreased [19,20].…”