ALTERATIONS OF FIBROBLAST METABOLISM IN EARLY LIGATURE-INDUCED PERIODONTITIS IN THE CYNOMOLGUS MONKEY

CELLULAR AND BIOCHEMICAL OBSERVATIONS were made of fibroblasts harvest ed from ligature-induced periodontitis and treated gingivitis areas in four adult female cynomolgus monkeys (Macaca fascicularis) to define the changes that occur in tl;e early periodontitis lesion. Compared wi th fibroblasts from the treated sites, fibroblasts from the diseased a reas had a significantly higher rate of proliferation, produced about two-thirds the amount of total protein and collagen, and failed to res pond to TGF-P, which normally stimulates extracellular matrix formatio n in mesenchymal cells. The diseased cells were also deficient in the activity of poly(ADP-ribose) synthetase, an enzyme involved in the rep air of DNA breaks such as occur from the insults of superoxide and oth er active radicals present in inflamed areas. Although the precise nat ure of these biochemical defects is not fully elucidated, they may hav e an important bearing on chronic periodontitis cases with a ''downhil l'' course.