|Budget Amount *help
¥1,900,000 (Direct Cost : ¥1,900,000)
Fiscal Year 1995 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1994 : ¥1,400,000 (Direct Cost : ¥1,400,000)
Many studies have shown that periodontal lesions in diabetic patients progress rapidly and resist treatment. Herein, we use the naturally occurring gingivitis rat (ODUS/Odu) with diabetes mellitus induced by injection of streptozotocin (STZ : 65mg/kg, i.v.) and the control rat (ODUS/Odu without STZ). One and 3 months after STZ injection, we intraperitoneally injected liquid paraffin. Four days later, we measured the pocket probing depth (PPD), and collected the blood sample and peritoneal macrophages from these rats. To elucidate the effect of diabetes on periodontal lesions, the chemotaxis and phagocytosis of macrophages were studied in ODUS/Odu with and without diabetes. One and 3 months after STZ injection, the PPD in the ODUS/Odu with diabetes was significantly deeper than in ODUS/Odu without diabetes (p<0.001). PPD was deeper at 3 months after STZ injection than at 1 month in ODUS/Odu with diabetes. Three months after STZ injection, there was a high positive correlation between blood glucose and triglycerides, or hemoglobin A_1C (p<0.01). In both experimental periods, the phagocytosis of macrophages in the diabetes group was significantly more suppressed than in that without diabetes (p<0.001). Three months after STZ injection, the macrophage chemotaxis was more suppressed in ODUS/Odu with diabetes than in those without diabetes. These findings stuggest that diabetes mellitus affects the chemotaxis and phagocytosis of macrophages in ODUS/Odu. Therefore, the host defense mechanism weakens, and worsens periodontal disease.