Hyaluronic acid metabolism in inflamed mesenterium of guinea pig.

Hyaluronic acid is known to play an important role in tissue remodeling and inflammatory process. To clarify the metabolism of hyaluronic acid in peritonitis, the biosynthesis of glycosaminoglycans in mesenterium was investigated in caseinate-induced peritonitis in guinea pig. Mesenterium showed acute inflammatory changes with polymorphonuclear leukocyte infiltration and produced much hyaluronic acid with a high molecular weight. Radioautography of inflamed tissue incubated with (3H)glucosamine demonstrated that radioactivity was incorporated predominantly by mesothelial cells and fibroblasts in the submesothelial cell layer. Intraperitoneal injection of human recombinant interleukin-1 alpha induced intraperitoneal accumulation of hyaluronic acid and its production by mesenterium. Heatlabile stimulating factor(s) for the biosynthesis of hyaluronic acid was present in the peritoneal fluid of inflamed guinea pigs. These results indicate that mesenterium is a hyaluronic acid-producing tissue and inflammatory changes of mesenterium are essential for the initiation and/or stimulation of hyaluronic acid production.