饮食或遗传所致胰岛素抵抗小鼠溶菌酶表达的对比研究

目的对比研究饮食或遗传所致胰岛素抵抗小鼠溶菌酶(lysozyme, LYZ)的表达。方法 m/m小鼠(糖脂代谢正常的C57BL/KsJ-m/m小鼠)经高脂喂养(high fat diet, m/m-HFD组)18周,筛选出6只小鼠为饮食诱导的胰岛素抵抗模型(insulinresistance,m/m-IR)组,随机从正常饮食喂养18周的糖脂代谢正常的C57BL/KsJ-m/m小鼠和Ⅱ型糖尿病模型C57BL/KsJ-db/db小鼠中各抽取6只作为m/m正常饮食组(normal controldiet,m/m-NCD)和遗传因素所致的胰岛素抵抗组(db/db),检测各组血样中糖脂代谢、空腹胰岛素水平(fasting insulin, FINS),检测回肠样本中LYZ的表达,并计算胰岛素敏感指数(insulin sensitivity index, QUICKI)和胰岛素抵抗指数(insulin resistance index, HOMA-IR)。结果干预18周后,与m/m-NCD组相比, m/m-HFD和db/db组小鼠血样中糖脂、胰岛素水平显著升高(P0.05),成模的小鼠QUICKI0.339, HOMA-IR2.69, db/db组胰岛素抵抗程度明显大于m/m-IR组;与m/m-NCD组相比, m/m-IR和db/db组小鼠回肠样本中LYZ表达均减少(P0.05)。结论胰岛素抵抗发生时回肠样本中LYZ蛋白的表达减少。

Comparative study on the expression of lysozyme in mice with insulin resistance induced by diet or genetics

Objective To study the expression of lysozyme (LYZ) in mice with insulin resistance induced by diet or genetics. Methods m/m mice (C57BL/KsJ mice with normal glucose and lipid metabolism) were fed with high fat (m/m-HFD group) for 18 weeks, and 6 mice were successfully screened for diet-induced insulin resistance model m/m In the m-IR group, 6 mice were randomly selected from the control group fed with a normal diet for 18 weeks and insulin resistance caused by genetic factors (gene-deficient C57BL/KsJ mice) as m/m-NCD group and db/db group , Using glucose oxidase method to detect blood fasting blood glucose (FBG) level, total cholesterol (TC) level, triglyceride (TG) level, oral glucose tolerance (OGTT) and insulin tolerance test (ITT) and calculate the area under the curve, Western blot technique was used to detect the expression of LYZ in ileal samples, ELISA method was used to detect blood fasting insulin level (FINS), and the insulin sensitivity index (QUICKI) and insulin resistance index (HOMA-IR) were calculated. Results After 18 weeks of intervention, the blood samples of m/m-HFD and db/db groups had increased glycolipids and insulin compared with the m/m-NCD group, and the model mice QUICKI<0.339, HOMA-IR >2.69, the degree of insulin resistance in the db/db group was significantly greater than that in the m/m-IR group; compared with the m/m-NCD group, the expression of LYZ in the ileal samples of the m/m-IR and db/db groups was reduced (p <0.05). Conclusion The expression of LYZ protein in ileal samples decreases when insulin resistance occurs.