过量运动对健康大鼠肾脏结构与功能的影响

Effects of excessive exercise on structure and function of kidney in healthy rats

目的:观察过量运动对健康大鼠肾脏结构与功能的影响并探讨其可能机制。方法:将30只健康Sprauge-Dawley(SD)大鼠按照随机数字表随机分为安静对照组和过量运动组,每组15只。安静对照组在鼠笼内安静饲养,过量运动组进行16周高强度跑台力竭运动。实验后,测定24 h尿蛋白(UP)、血尿素氮(BUN)和血清肌酐(SCr)含量评价肾功能;分别行HE、Masson染色观察肾脏组织病理学改变,同时获取肾小球和肾小管损伤评分以及纤维化指数(FI);免疫印迹测定转化生长因子-β1(TGF-β1)、基质金属蛋白酶-9(MMP-9)、α-平滑肌肌动蛋白(α-SMA)和E-钙黏蛋白(E-CA)蛋白表达量。结果:与安静对照组比较,过量运动组肾脏结构异常,肾小球损伤评分、肾小管损伤评分、FI、UP、BUN和SCr增加(t分别为-6.895、-7.365、-9.234、-4.964、-7.753、-16.444,均P<0.05),MMP-9蛋白表达下调(t=5.077,P<0.05),而TGF-β1、α-SMA和E-CA蛋白表达差异无统计学意义(t分别为-1.801、-1.129、1.585,均P>0.05)。结论:长期过量运动可导致健康大鼠肾脏损伤、纤维化及肾功能下降,其机制可能与肾脏胶原降解受抑制有关。

Objective:To observe the effect of excessive exercise on the structure and function of kidney in healthy rats and explore the possible mechanism. Methods:A total of 30 healthy Sprauge-Dawley(SD)rats were randomly divided into rest control group(RC) and excessive exercise(EE)group according to the random number table,with 15 rats in each group. The rats in RC group were reared quietly in cages,while those of EE group were given high-intensity treadmill exhaustive exercise for 16 weeks. After the experiment,24hour urinary protein(UP),blood urea nitrogen(BUN) and serum creatinine(SCr) were measured to evaluate renal function;renal histopathological changes were observed by HE and Masson staining,glomerular and tubular injury score and fibrosis index(FI)were obtained;Western blotting method was used to detect the protein expressions of transforming growth factor β1(TGF-β1),matrix metalloproteinase-9(MMP-9),α-smooth muscle actin(α-SMA)and E-cadherin(E-CA). Results:Compared with RC group,the renal structure of EE group was abnormal,glomerular injury score,renal tubular injury score,FI,UP,BUN and SCr were increased(t =-6.895,-7.365,-9.234,-4.964,-7.753,-16.444,P <0.05),and the expression of MMP-9 protein was downregulated(t = 5. 077,P < 0. 05),however,there was no significant difference in the expression of TGF-β1,α-SMA and E-CA protein(t =-1. 801,-1. 129,1. 585,P > 0. 05). Conclusion:Excessive exercise may induce renal injury,fibrosisand decline of renal function in healthy rats,which may be related to the inhibiting collagen degradation in the kidney.