吡格列酮对STZ诱导糖尿病大鼠肌肉组织胰岛素抵抗的作用

目的]观察吡格列酮（Pioglitazone，Piog）对DM大鼠肌肉组织的病理学影响以及免疫球蛋白在肌肉组织表达的变化，探讨其是否通过免疫调节机制来减轻胰岛素抵抗（Insulin resistance，IR）。方法]雄性SD大鼠72只，由链脲佐菌素（streptozocin，STZ）诱导造成DM模型后随机分为Piog干预组（Piog组）、环孢菌素A干预组（CsA组）、无干预组（DM组），每组24只。另取24只雄性SD大鼠设为正常对照组（NOR组）。所有大鼠给药16周后处死。处死前测定各组大鼠空腹血糖和胰岛素，计算胰岛素抵抗指数HOME-IR。对各组大鼠的肌肉组织，采用HE染色、Mallory氏磷钨酸苏木素染色法观察的病理学改变；免疫组织化学法观察免疫球蛋白的异常沉积。结果]与NOR组相比，DM组血糖和HOME-IR明显升高。Piog能明显降低HOME-IR。与NOR组相比DM组大鼠肌肉组织肌纤维束明显变窄，肌纤维间的间隙变大，间质增生，肌纤维局部有空泡样改变；Piog组大鼠肌肉组织组的病理学与正常组接近，与CsA组无明显差别。NOR组IgA、IgG和IgM在肌肉组织中均无明显阳性表达，DM组大鼠组有较强的阳性表达，Piog组也有阳性表达，但明显低于DM组。结论]DM大鼠肌肉组织存在IR和免疫损伤。Piog能明显改善DM大鼠肌肉组织的病理学结构，并减少免疫球蛋白在肌肉组织的表达和沉积，对DM大鼠肌肉组织的免疫损伤具有明显保护作用。

Effect of pioglitazone on insulin resistance in muscle tissues of diabetic rats induced by STZ

Objective]To observe the effects of pioglitazone （Piog） on pathologic changes and immunoglobulin expression of muscle tissues in STZ-induced diabetic rats and to find out whether Piog reduce insulin resistance （IR） through immune regulation mechanism. Methods] Seventy-two male SD rats induced diabetic model by STZ, were randomly divided into Piog group （group Piog）, cyelosporin A treatment group （CsA group）, and non intervention group （group DM）, 24 rats in each group. Another twenty-four male SD rats were treated as normal control group （group NOR）. All rats were killed after 16 weeks. At the end of the determination of fasting blood glucose and insulin, insulin resistance index was calculated by HOME-IR. The rats of muscle tissue, using HE staining, Mallory＇s phosphotungstic acid hematoxylin staining was observed the pathological changes, and abnormal deposition of the immune globulin was observed by immunohistochemistry method. Results] Compared with group NOR, the blood glucose and HOME-IR of group DM increased. Piog could significantly reduce HOME-IR. Muscle fiber bundle was narrow, the gap between the muscle fiber size, interstitial hyperplasia, muscle fiber local vacuolar changes were observed in group DM. The changes in group Piog were close to normal muscle, comparative to group CsA. IgA, IgG and IgM of muscle tissues in group NOR had no significant positive expression, but had stronger expressions in the rats of group DM. Group Piog also had positive expression of IgA, IgG and IgM, but significantly lower than that in group DM. Conclu- sions ] The presence of IR and immune injury were observed in muscle tissues of diabetic rats. Piog could obviously improve pathological muscle tissues of diabetic rats, and reduce expression of immunoglobulin in muscle tissues, thereby had obvious protective effect on immune injury of muscle tissue in diabetic rats.