炎症因子chemerin在有氧运动改善动脉粥样硬化大鼠血脂和主动脉硬化中的作用

Effects of Chemerin on Aerobic Exercise-induced Improvements of Blood Lipid and Aortic Sclerosis in Atherosclerosis Rats

目的:研究炎症因子chemerin在有氧运动改善动脉粥样硬化大鼠血脂和主动脉硬化中的作用。方法:将30只雄性SD大鼠随机分为2组,AS造模组20只,采用一次性腹腔注射维生素D3(60万IU/kg)联合8周高脂饲料喂养的方法制备AS大鼠模型;正常对照组(Con)10只,腹腔一次性注射等量的生理盐水,并喂以8周普通饲料。建模成功的AS大鼠被随机分为AS组和运动+AS(EAS)组。EAS组大鼠在跑台上进行为期4周中等强度的有氧运动,每周运动6 d。油红O染色和HE染色检测AS程度,全自动生化分析仪检测大鼠血脂(血清TC、TG、LDL、HDL水平),ELISA检测血清chemerin水平,以及real time PCR和Western blot检测大鼠肝脏chemerin的mRNA和蛋白表达水平。结果:(1)与Con组相比,AS组大鼠出现血脂紊乱(血清TC、TG、LDL水平显著升高,HDL显著降低),以及主动脉粥样斑块,斑块处血管中膜的平滑肌细胞增生、排列紊乱,但AS组大鼠的空腹血糖无变化。(2)与AS组相比,EAS组大鼠的TC、TG、LDL水平显著降低、主动脉AS的大体和镜下病理改变均显著减轻;肾周脂肪量显著减少,以及空腹血糖无变化。(3)与Con组相比,AS组大鼠的血清chemerin、肝chemerin的mRNA和蛋白水平均显著升高。(4)与AS组相比,EAS组大鼠的血清chemerin、肝chemerin的mRNA和蛋白水平均显著降低。结论:AS大鼠的血清chemerin、肝chemerin的mRNA和蛋白水平均显著升高;4周有氧运动改善AS大鼠的血脂、减少肾周脂肪量和减轻AS程度,这可能与其降低血清和肝的chemerin水平有关。

To investigate the effects of chemerin on aerobic exercise - induced improvements of blood lipid and aortic sclerosis in atherosclerosis （AS） rats. Methods： Thirty male SD rats were randomly divided into AS model group （ n = 20） and control group （ Con,n = 10） ,the former rats were fed with 8 - week high fat diet after an intra - peritoneal injection of vitamin D3 （600 thousand IU/kg body weight） to establish AS model rats while the latter fed with normal diet after an injection of the same amount of normal saline. The AS model rats were further randomly divided into 2 groups. AS group and exercise AS （EAS） group, 8 rats in each group. The EAS rats participated in moderate intensity aerobic exercise on a treadmill with an increasing load for 4 weeks ,6 days per week. The severity of AS were evaluated according to the plaques appeared in gross aortas stained with oil red O as well as the pathological changes of aortic paraffin section stained with HE. Blood lipid （ serum levels of triglyceride （ TG ）, total cholesterol （ TC）, low - density lipoprotein （ LDL）, and high density lipoprotein （ HDL ）） were detected using full automatic biochemical analyzer. Fasting glucose were determined by Roche glucometer. Serum levels of chemerin were measured by ELISA. The mRNA and protein expression of chemerin in livers were detected by real time PCR and Western blot,respectively. Results： 1） Successful establishment of AS model rats： compared with control,significant increases of serum levels of TC, TG and LDL as well as decrease of serum HDL were showed in the AS rats; and the atherosclerotic plaque appeared in the gross aortas and the proliferation and arrangement disorders of smooth muscle ceils in aorta membrane were found in the AS rats. 2） Compared with AS group, significant improvements of blood lipid （lower of TC, TG and LDL ）, as well as decreases of relative weight of perirenal adipose and AS severity （ alleviations of gross and pathological disorders of aortas） were found in EAS rats. 3 ） The serum chemerin as well as the mRNA and protein levels of chemerin inlivers were significant higher in the AS rats than that of Con. 4） The levels of chemerin in serum and livers were significant down - regulated in EAS rats compared with AS rats. Conclusions： 1 ） The serum chemerin as well as the mRNA and protein levels of chemerin in livers were increased in AS rats. 2） Aerobic exercise induced improvements of blood lipid and severity of AS in aortas, which may be associated with the decreases of chemerin in serum and livers.