牙周炎对大鼠血清瘦素水平及胰岛素抵抗的影响

目的探讨实验性牙周炎对正常和肥胖大鼠血清瘦素水平及胰岛素抵抗的影响。方法 32只雄性SD大鼠随机等量分为肥胖组、牙周炎组、肥胖与牙周炎复合组以及正常对照组。采用皮下注射谷氨酸钠的方法建立肥胖大鼠模型,结扎双侧上颌磨牙建立牙周炎模型。4组大鼠饲养20周后处死,采集血样,运用酶联免疫吸附法检测大鼠血清中瘦素,空腹胰岛素和空腹血糖水平,并计算胰岛素抵抗指数。结果牙周炎组和肥胖与牙周炎复合组大鼠的血清瘦素浓度分别为（11.10±3.36）ng/mL和（50.51±7.60）ng/mL,空腹血糖分别为（12.83±1.87）mmol/L和（7.10±1.32）mmol/L,分别高于正常对照组和肥胖组,差异均有统计学意义（P〈0.05）。血清瘦素水平的升高与胰岛素抵抗指数存在正相关关系。结论牙周炎可诱导正常与肥胖大鼠的血清瘦素水平和胰岛素抵抗指数升高,尤其是肥胖大鼠更显著,牙周炎可加重其高瘦素血症和胰岛素抵抗状态。

Effect of periodontitis on serum leptin levels and insulin resistance in rat model

Objective To investigate the effects of experimental periodontitis on serum leptin levels and insulin resistante in normal and obese rat models. Methods Thirty-two natal SD male rats were randomly divided into four groups of 8 rats each, respectively： obese rats without periodontitis（OB group）, normal rats with periodontitis（CP group） , obese rats with periodontitis（ OB ＋ CP group）and normal rats without periodontitis（ C group）. In the OB group and OB ＋ CP group, rats received subcutaneous injection of MSG on alternate days for the first 10 postnatal days. Ligation method was used to induce experimental periodontitis. At 20 weeks of age, rats were sacrificed and serum samples were collected. Concentrations of serum leptin and insulin were determined using enzyme-linked immunosorbent assay（ELISA） kit; glu- cose levels were measured by glucose oxidase method. Insulin resistance was calculated using the homeostasis model assessment （HOMA-IR）. Results The mean levels of serum leptin in the CP and OB ＋ CP groups were （ 11. 10 ± 3.36） ng/ml, and （50.51± 7.60） ng/mL and fasting blood glucose level were （ 12.83 ± 1. 87 ） mmol/L and （7. 10 ± 1.32） mmol/L, which were significantly greater than that of the C group and OB group, respectively. Significant positive relationships were observed between HOMA-IR and leptin expression levels in serum. Conclusion Experimental periodontitis can upregulate the levels of serum leptin and HOMA-IR in normal and obese rat model; furthermore, periodontitis can deteriorate insulin resistance in obese rat model.