摘要
目的:观察低氧训练对大鼠心、肝、肾、海马组织细胞凋亡及HIF-1α、Bax、Bcl-2表达的影响,探讨低氧训练的适应机理。方法:70只SD大鼠按体重随机分为7组,每组10只,即正常对照组(A)、高住8 h组(B)、高住12 h组(C)、常氧运动组(D)、8 h高住低练组(E)、12 h高住低练组(F)和一次力竭运动组(G)。D、E、F组大鼠每天在坡度为0的动物跑台上,以25 m/min的速度训练1 h。训练后,分别将B、E组和C、F组依次放入氧浓度为12.5%(相当于海拔4000 m)的低氧舱内8 h和12h。5 d/周,实验期4周。最后一次训练,B、C、D、E、F、G组以25 m/min的速度训练至力竭,24 h后大鼠均实施速眠新II腹腔麻醉后心脏取血致死,取材。采用HE染色、原位末端脱氧核糖核苷酸转移酶介导的dUTP缺口末端标记法(TUNEL)及蛋白免疫组织化学法检测大鼠心、肝、肾、海马组织细胞凋亡和HIF-1α、Bcl-2、Bax表达。结果:(1)随时间延长,高住组大鼠心、肝、肾、海马组织出现棕褐色凋亡细胞;12 h高住低练组大鼠心、肝、肾组织可见细胞肿胀、间隙明显增大,凋亡细胞核随时间延长明显增多,而海马组织凋亡细胞核明显减少;常氧运动组可见较多凋亡细胞核,一次力竭运动组可见大量凋亡细胞核。(2)高住组、常氧运动组、高住低练组、一次力竭运动组心、肝、肾细胞凋亡指数、Bax、HIF-1α表达显著高于正常对照组(P<0.05),而高住12 h组、常氧运动组、一次力竭运动组海马区细胞凋亡指数、Bax、HIF-1α显著高于正常对照组(P<0.05)。12 h高住低练组心、肝、肾凋亡指数、Bax及HIF-1α表达显著高于常氧运动组(P<0.05),而高住低练组海马区细胞凋亡指数、Bax及HIF-1α表达显著低于常氧运动组(P<0.05)。高住组、常氧运动组、8 h高住低练组心、肝、肾、海马细胞凋亡指数、凋亡发生率及Bax、HIF-1α表达显著低于一次力竭运动组(P<0.05);12 h高住低练组心、肝、肾凋亡发生率、凋亡指数及Bax、HIF-1α表达显著高于高住组和常氧运动组(P<0.05),而高住组和常氧运动组及一次力竭运动组海马组织凋亡发生率、凋亡指数及Bax、HIF-1α表达显著高于高住低练组。(3)各实验组心、肝、肾Bcl-2蛋白表达显著高于正常对照组(P<0.05);与一次力竭运动组相比,高住8h组、常氧运动组有下降趋势,但无统计学意义;随着低氧暴露时间延长,高住组心、肝、肾Bcl-2蛋白表达增加不明显,高住低练组Bcl-2蛋白表达随低氧暴露时间延长而增加;而高住组、高住低练组海马区Bcl-2蛋白表达随低氧暴露时间延长而降低。结论:(1)耐力运动、8 h和12 h的4000 m低氧暴露、8 h高住低练可提高大鼠有氧代谢能力。(2)低氧、耐力运动、高住低练、一次力竭运动诱导大鼠心、肝、肾、海马组织HIF-1α、Bcl-2及Bax蛋白表达,细胞凋亡率与凋亡指数及损伤与低氧刺激和大强度运动有关,12 h高住低练及一次力竭运动对运动能力影响最明显。(3)Bcl-2与Bax参与调控心、肝、肾、海马组织细胞凋亡,HIF-1α表达可能协同Bcl-2家族调控凋亡相关因子的表达,在低氧训练导致的组织细胞凋亡中发挥双重效应。(4)低氧刺激对不同组织影响不一,对心、肝、肾影响较大,海马组织相对稳定。
Objective To observe the hypoxic training on the apoptosis of heart,liver,kidney and hippocampus,and on the expressions of HIF-1α,Bax and Bcl-2.Methods Seventy SD rats were randomly and equally divided into following 7 groups：normal control group（A）,high-living 8-hour group（B）,high-living 12-hour group（C）,regular aerobic exercise group（D）,8-hour HiLo training group（E）,12-hour HiLo training group（F） and an exhaustive exercise group（G）.Rats in groups D,E and F underwent treadmill training with the speed of 25m/min for 1 hour per day,5 days per week.After that,rats in groups B,E,C and F were transferred to the chamber with oxygen concentration of 12.5%（simulated 4000m altitude） for 8 hours or 12 hours,respectively.The experiment lasted for 4 weeks.24 hours after the last training at the speed of 25 m/min to exhaustion,rats in groups B,C,D,E,F,and G were decapitated under anesthesia and their blood was collected.The apoptosis in cells of heart,liver,kidney and hippocampus,and the expressions of HIF-1α,Bax and Bcl-2 were detected by HE staining,TUNEL（terminal deoxynucleotydyl transferase-mediated dUTP nick end labeling）,and immunohistochemistry.Results（1）Brown apoptotic cells of heart,liver,kidney and hippocampus appeared with the prolonging of staying duration in all high-living groups;Swelling and clearance of cells in heart,liver and kidney appeared,and the number of apoptotic nuclei increased with prolonging of staying duration in group F,while nuclear apoptosis in hippocampus reduced significantly;Numerous apoptotic nuclei in groups D and G were observed.（2）Cell apoptosis index,and expressions of Bax and HIF-1α of heart,liver,kidney increased significantly in groups B,C,D,E,F and G,as compared with that in group A（P〈0.05）,especially those of hippocampus in group C,D and G.Cell apoptosis index,and expressions of Bax and HIF-1α of heart,liver,kidney in group F were significantly higher than in group D（P〈0.05）,while those of hippocampus in groups E and F were significantly lower than in group D（P〈0.05）.The apoptotic index,incidence of apoptosis,and expression of Bax and HIF-1 of heart,liver,kidney,and hippocampus were significantly lower in groups B,C,D and E than in group F（P〈0.05）,and those in group F were significantly higher than in groups B,C and D（P〈0.05） and those in B,C and G were significantly higher than in groups E and F.（3）As compared with the control group,Bcl-2 protein expression in other groups significantly increased（P〈0.05）.Conclusions（1）Endurance training,8-and 12-hour hypoxic exposure could improve aerobic capacity of SD rats.（2）Hypoxia,endurance training,living-high training-low and exhaustive exercise could induce protein expression of HIF-1a,Bcl-2 and Bax in heart,liver,kidney and hippocampus.Cell apoptosis rate and apoptosis index,and pathological changes were related to the hypoxic stimulus and intensive exercise.（3）Bcl-2 and Bax involved in the regulation of cell apoptosis in the heart,liver,kidney,and hippocampus,in which HIF-1α probably played a synergistic role in coordination with Bcl-2 family.（4）Hypoxia affected the heart,liver,and kidney more obviously than hippocampus.
出处
《中国运动医学杂志》
CAS
CSCD
北大核心
2012年第2期146-156,共11页
Chinese Journal of Sports Medicine
基金
长沙市科技局计划项目(K0803144-31)
湖南省科技厅计划项目(2007FG3089)
湖南省自然科学基金(05JJ30066)
2009年湖南省研究生科研创新项目(CX2009B105)
