不同强度有氧运动对糖尿病大鼠肝脏SREBP及肝脂肪变的影响

Effect of different intensity exercise on SREBP and liver steatosis in diabetes rats

目的:通过探讨不同强度有氧运动对糖尿病大鼠肝脏SREBP及脂肪变的影响,为运动改善胰岛素抵抗和防治糖尿病性脂肪肝提供理论依据。方法:通过高脂饮食喂养配合小剂量STZ腹腔注射建立糖尿病大鼠模型,并随机分为安静组(PA)和小中大三种强度运动组(LIE,MIE,HIE),分别进行10 m/min、15 m/min和20 m/min的有氧耐力跑台运动,1 h/d,5 d/w,持续运动训练6周。6周后测试大鼠空腹血糖、糖化血清蛋白、胰岛素和肝脏SREBP含量、肝脏脂肪浸润情况,并计算胰岛素抵抗指数、胰岛素敏感指数。结果:糖尿病大鼠经6周运动训练后,与PA组相比较,血糖、糖化血清蛋白和胰岛素抵抗指数均有显著降低;LIE、MIE及HIE组大鼠肝脏SREBP呈显著性降低(P<0.01,P<0.01,P<0.05);肝脏HE染色发现,PA组大鼠肝细胞正常的条索状结构破坏,部分细胞中有脂质沉积,并出现脂肪空泡,有少部分肝细胞发生溶解性坏死。LIE、MIE和HIE组大鼠肝细胞有明显改善,且以MIE组脂肪浸润最少。结论:6周的运动干预能有效降低糖尿病大鼠肝脏SREBP蛋白含量,进而减少肝细胞内脂质沉积,维持肝细胞功能,有利于降低肝脏胰岛素抵抗,且以中低强度有氧运动效果较好。

Objective：To investigate the changes of SREBP and liver steatosis after different intensity exercise on diabetes rats, which provide a theoretical basis to exercise improving insulin resistance and prevention and treatment of diabetic fatty liver. Methods ： Rat model of type 2 diabetes were es- tablished by high - fat diet with low - dose streptozotocin intraperitoneally injected, and randomly divided into quiet group （PA） and 3 exercising groups （ LIE, MIE, HIE）. After adapting to treadmill exercise, the 3 exercising groups do lh treadmill running by 10m/min, 15m/rain and 20m/min treadmill speed respectively, lh/d, 5d/w, continuous training for 6 weeks. Then tested FBG, GSP, Ins and the content SREBP of liver, HE staining of liver fat infiltration, and Calculated IRI, ISI, HBCI. Results ： After 6 weeks of exercise training, compared with PA, the FBG, GSP,IRI and liverSREBP of 3 exercising groups were all decreased. HE staining of liver shows that PA group of nor- real rat liver cells in cord - like structural damage, some cells have lipid deposition and fat vacuoles, a small solubility of necrosis of liver cells. LIE, MIE and HIE rat liver cells had greatly im- proved and fat infiltration by MIE Group minimum. Conclusion： The 6 -week exercise intervention can reduce the protein content of SREBP in liver of diabetic rats, thereby reducing lipid accumulation in liver cells, help reduce hepatic insulin resistance, and the low and middle intensity aerobic exercise is better.