血清SOD、MDA、NO在波动性高血糖糖尿病大鼠中的表达

Expression of Serum SOD,MDA and NO Levels in High Blood Glucose Fluctuation in Diabetic Rats

目的观察血糖波动对糖尿病大鼠血清超氧化物歧化酶(SOD)、丙二醛(MDA)、一氧化氮(NO)表达水平的影响。方法SD大鼠60只,随机分成正常饲料喂养组(正常组,n=20)和高糖高脂饲料喂养模型组(模型组,n=40),模型组SD大鼠6周后用小剂量链尿佐菌素(STZ)建立SD大鼠糖尿病模型,之后随机分为持续高血糖组(MS组,n=20)和血糖波动组(MF组,n=20),MF组错时腹腔注射葡萄糖、胰岛素,制备糖尿病血糖波动大鼠模型,正常组和MS组均同时腹腔注射等量生理盐水。测定各组大鼠血糖(Glu)、甘油三酯(TG)、高密度脂蛋白(HDL-C)、低密度脂蛋白(LDL-C)及血清超氧化物歧化酶(SOD)、丙二醛(MDA)、一氧化氮(NO)水平。结果 (1)MS和MF组TG、LDL-C均明显高于正常组(P<0.01),而HDL-C均显著低于正常组(P<0.01);(2)与正常组比较,MS组和MF组SOD、MDA、NO值均有统计学差异(P均<0.05),MF组SOD、MDA、NO水平高于MS组(P<0.05)。结论 2型糖尿病大鼠体内存在血管内皮损伤和氧化应激;持续高血糖可以损伤血管内皮细胞;血糖的剧烈波动较持续性高血糖引起SOD、MDA、NO变化更为显著,可能导致更为严重的血管内皮细胞损伤。

Objective To observe the effects of blood-glucose fluctuation on serum superoxide dismutase （SOD）, malondialdehyde （MDA）, and nitric oxide （ NO ） levels in rat models of diabetes mellitns. Methods Sixty male Sprague- Dawley rats were randomly divided into normal group （n = 20） and model group （ n = 40）, The diabetic rat model was established by injection of a small dose of streptozotoein （STZ） after feeding the model group SD rats with high-sugar high-fat diet for 6 weeks. The persistent high glucose diabetic rat model group （MS） was established by intraper- itoneal injection of glucose, and the bloed-glucose fluctuation rat medel group （MF） was developed by alternative intraperitoneal injection of insulin and glucose. Serum glucose （ Glu ） was measured at 6 weeks after MF model establishment, triglyceride （TG）, low density lipopretein （ LDL-C ）, high density lipoprotein （HDL-C）, SOD, MDA, and NO were measured at 12 weeks. Results （ 1 ） 12 weeks after intravenous injection of STZ, the lev- els of TG and LDL-C in the MS and MF groups were significandy increased （all P 〈 0.01 ）, and HDL-C was significandy decreased compared with those of the N group （P 〈 0.01 ）. （2） Compared with the normal group, the expression levels of SOD, MDA, NO in the MS and MF groups were all changed significantly （all P 〈 0.05 ）, while the MF group were significantly higher than those of the MS groups （ all P 〈 0.01 ）. Conclusion （ 1 ） Vascular endothelium cell （VEC） injury and oxidative stress exist in type 2 diabetic rat, （2） Hyperglycemia can lead to VEC injury. （ 3 ） Glucose fluctuation induces more obvious changes than hyperglycemia in express of SOD, MDA, and NO, which may consequently induces more serious en- dothelial dysfunction than hyperglycemia.