| 摘要: |
| 目的 探讨有氧运动对高脂血症大鼠血脂的影响及其作用机制。方法 将120只8周龄健康雄性SD大鼠随机分为正常对照组、高脂饮食组、SBC-115076组和有氧运动组，每组30只。正常对照组饲喂标准饲料，其余3组饲喂高脂饲料构建大鼠高脂血症模型；SBC-115076组每周注射前蛋白转化酶枯草溶菌素9（PCSK9）抑制剂SBC-115076（8 mg/kg）1次，连续8周；有氧运动组进行无负重游泳，每周6 d，共持续8周。8周后处死大鼠，采集血液标本，测定血清三酰甘油（TG）、总胆固醇（TC）、低密度脂蛋白（LDL）、高密度脂蛋白（HDL）水平。取胸主动脉标本，经H-E染色观察主动脉病理学改变。取肝组织标本，采用实时荧光定量PCR、蛋白质印迹分析和免疫荧光法检测肝组织中PCSK9、低密度脂蛋白受体（LDLR）和胆固醇调节元件结合蛋白（SREBP）在mRNA和蛋白水平的表达。结果 高脂饮食组大鼠血清TG、TC和LDL水平高于对照组，HDL水平低于对照组（P<0.01）；SBC-115076组和有氧运动组大鼠血清TG、TC、LDL水平低于高脂饮食组，HDL水平高于高脂饮食组（P<0.01）。高脂饮食组大鼠主动脉壁内膜增厚，内皮细胞损伤脱落；与高脂饮食组相比，有氧运动组大鼠主动脉内膜增厚明显减轻，内皮损伤较少。与对照组相比，高脂饮食组大鼠肝组织中PCSK9、SREBP1和SREBP2的mRNA及蛋白表达水平升高，LDLR的mRNA及蛋白表达水平降低（P<0.01）；与高脂饮食组相比，SBC-115076组和有氧运动组大鼠肝组织中PCSK9、SREBP1和SREBP2的mRNA及蛋白表达水平降低，LDLR的mRNA及蛋白表达水平升高（P<0.01）。结论 有氧运动能降低高脂血症大鼠血清TG、TC和LDL水平，升高HDL水平，并减轻主动脉内膜增厚。其机制可能与降低PCSK9和SREBP蛋白的表达，从而解除对LDLR的抑制有关。 |
| 关键词: 高脂血症 有氧运动 前蛋白转化酶枯草溶菌素9 胆固醇调节元件结合蛋白 低密度脂蛋白受体 |
| DOI：10.16781/j.0258-879x.2019.04.0412 |
| 投稿时间：2018-09-18修订日期：2018-12-07 |
| 基金项目:上海市卫生和计划生育委员会科研课题（201640282）. |
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| Effect of aerobic exercise on blood lipid of hyperlipidemia rats and its mechanism |
| ZHAO Ya1,ZHANG Song2*,LI Yuan-yuan1,SHI Yun1,NI Ye1,LI Yan-yan2,YANG Jie2,LIU Wei2 |
(1. Department of Cardiology, Kongjiang Hospital of Yangpu District, Shanghai 200093, China;
2. Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200093, China
*Corresponding author) |
| Abstract: |
| Objective To explore the effect of aerobic exercise on blood lipid of hyperlipidemia rats and its mechanism. Methods A total of 120 healthy male SD rats aged 8 weeks were randomized into normal control group, high-fat diet (HF) group, SBC-115076 group and aerobic exercise group, with 30 rats in each group. The rats in the normal control group were fed with standard diet, and the rats in the other 3 groups were fed with HF to establish hyperlipidemia rat model. The rats in the SBC-115076 group were injected with proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor SBC-115076 (8 mg/kg) once a week for 8 weeks, and the rats in the aerobic exercise group underwent swimming without load 6 days a week for 8 weeks. After 8 weeks, the rats were sacrificed and the blood samples were collected to determine the levels of serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL) and high-density lipoprotein (HDL). Pathological changes of thoracic aorta were observed using H-E staining. The mRNA and protein expression levels of PCSK9, low-density lipoprotein receptor (LDLR) and sterol regulatory element binding protein (SREBP) in the hepatic tissues were detected by quantitative real-time PCR, Western blotting and immunofluorescence. Results Compared with the normal control group, the levels of serum TG, TC and LDL of the rats were significantly higher in the HF group, and the level of HDL was significantly lower (P<0.01). Compared with the HF group, the levels of serum TG, TC and LDL of the rats were significantly lower in the SBC-115076 and aerobic exercise groups, and the level of HDL was significantly higher (P<0.01). In the HF rats, the aortic tunica intima was thickened and endothelial cells were damaged and exfoliated. Compared with the HF group, the aortic intima thickening was reduced and endothelial damage was less in the aerobic exercise group. Compared with the normal control group, the mRNA and protein expression levels of PCSK9, SREBP1 and SREBP2 were significantly higher in the HF group, and the mRNA and protein expression levels of LDLR were significantly lower (P<0.01). Compared with the HF group, the mRNA and protein expression levels of PCSK9, SREBP1 and SREBP2 were significantly lower, and the mRNA and protein expression levels of LDLR were significantly higher (P<0.01). Conclusion Aerobic exercise can down-regulate the expression of TG, TC and LDL, up-regulate the expression of HDL, and alleviate the intimal thickening of aorta. The mechanism may be related to down-regulating the expression of PCSK9 and SREBPs, thus eliminating the inhibition of LDLR. |
| Key words: hyperlipidemia aerobic exercise proprotein convertase subtilisin/kexin type 9 sterol regulatory element binding proteins low-density lipoprotein receptor |
