高住低练大鼠肝细胞凋亡与bax,bcl-2和HIF-1α之间的关系

Relation of Living High/Training Low on Hepatic Apoptosis between Bax,Bcl-2 and HIF-1α in Sprague-Dauley Rats

探讨"高住低练"肝细胞凋亡与凋亡调控基因(包括HIF-1α)之间关系,为低氧训练提供科研资料。方法:健康成年雄性SD大鼠60只,随机分为6组。安静对照组(C)不训练,不进行低氧暴露;低氧暴露组(HE)和高住低练组(Hilo)每天低氧暴露(氧浓度12.6%,相当于海拔4 000 m)8 h和12 h,5 d/周,共4周;常氧运动组和高住低练组每天均以25 m/min的速度训练1 h,5 d/周,共4周。采用免疫组织化学方法和计算机显微图像分析系统分析bax、bcl-2和HIF-1α阳性表达、阳性物质的定位及定量。结果:1)与C组相比实验各组细胞凋亡指数著性升高(p<0.01),Hilo组凋亡指数显著高于HE组和T组(p<0.01),但12Hilo与8Hilo之间无显著性差异;2)Hilo组的bax蛋白表达与HE组和T组相比显著增加(p<0.05),随着低氧暴露时间的延长,呈增长趋势;TUNEL与bax呈正相关(r=0.693,P<0.01);3)HE组bcl-2蛋白表达显著高于C组,12 hHE组的bcl-2蛋白表达比8hHE组显著下降(p<0.05);12Hilo组bcl-2蛋白表达比8Hilo组显著下降,但明显高于C组(p<0.05);4)肝组织bax/bcl-2值显示,C组与12 hHE组和12Hilo组相比具有显著性意义(p<0.05);T组与Hilo组相比具有非常显著性意义(p<0.01);5)HIF-1α与bax呈高度正相关(r=0.958,p<0.01)。结论:bax、bcl-2与HIF-1α基因参与调控肝细胞的凋亡;HIF-1α与肝细胞凋亡呈正相关,HIF-1α可能调控bax和bcl-2,并与bax呈高度正相关,调控bax高表达而促进肝细胞凋亡。

This research studies hepatic apoptotic gene,and applies research data for hypoxic training in sports practice applications.It attempts to explore the relation between apoptotic gene and apoptosis on living high/training low.60 male SD rats are randomly divided into six groups.Group C do not hold hypoxia and training.Groups HE and Hilo are held in hypoxia chamber（12.5% concentrations of oxygen,simulated as a altitude of 4 000 m） with 8h and 12h each day,5 days per week for 4 weeks.Groups T and Hilo are trained at the speed of the 25 m/min for 1 hour each day,5 days per week for 4 weeks.Immunohistochemical and computer image processing technique are applied to detect positive expression and quantificational analysis for HIF-1α,bax and bcl-2 protein.As compared with group C,the index of apoptosis increases significantly in other experimental groups（p0.01）.The index of apoptosis occurs significantly in group Hilo more than HE and T（p0.01）.The index of apoptosis has non-significance in group 8Hilo and 12Hilo.As compared with HE and C,bax in group Hilo increases significantly（p0.05）,and increases slightly with hypoxia long time.It demonstrates the correlation（r=-0.693,p0.01） between TUNEL and bax.Bcl2 in group HE expresses more than group C,then bcl-2 in group 12hHE expresses lower than 8hHE（p0.05）;As compared with 8 Hilo,it shows decrease in group 12Hilo,then it is still higher than group C（p0.05）.As compared with C, bax/ bcl-2 shows that there is prominent significance in groups 12hHE and 12Hilo （p0.05）,and as compared with T,there is prominent significance in groups Hilo（p0.01）.It demonstrates the correlation（r=-0.958,p0.01） between HIF-1α and bax.In conclusion,Bax,bcl-2 and HIF-1α gene participates to adjust liver apoptosis.HIF-1αprotein may adjust bax and bcl-2,and it is related with bax prominently,HIF-1αpromotes bax protein expression to induce liver apoptosis.