急性力竭运动后大鼠心肌细胞AngII受体表达的时间研究

目的：通过对急性力竭运动后不同时间大鼠心肌细胞血管紧张素Ⅱ受体AT，R和AT2R的表达变化以及心肌细胞凋亡进行研究，探讨血管紧张素Ⅱ受体与运动引起的心肌细胞凋亡之间的关系，揭示运动影响心脏的分子机制．方法：SD健康大鼠40只随机分为安静组（An=10）和力竭运动组（B，n=30），B组在运动后又分为3个亚组即0h、6h和24h处死组．运动组大鼠进行运动速度为（25±2）m／rain，跑台坡度为0。力竭运动．应用RT—PCR法测定AIFmRNA的表达，TUNEL法测试心肌细胞凋亡指数，用Westernblotting方法测试心肌细胞ATlR和AT2R表达．结果：急性力竭运动后0h、6h和24hAIFrtlRNA表达量分别为6．69（P〈0．05）、9．32（P〈0．05）和10．82倍（P〈.．001）；运动后0h、6h和24hA1分别为（17．10±3．6）％（P〈0．001）、（33．3±10．4）％（P〈0．001）和（30．7±9．2）％（P〈0．001）；运动后0h、6h和24h心肌细胞ATlR蛋白表这分别增加5．16％（P〉0．05）、30．19％（P〈0．05）和64．44％（P〈0．05）而AT2R蛋白表达分别增加2．15％（P〉0．05）、10．12％（P〉0．05）和28．30％（P〈0．05）．结论：急性力竭运动后AT，R和AT2R表达增加，24h后仍然维持较高水平的表达；运动后AIFmRNA表达增加，运动后6h表达量达最大，24h开始下降．而ATlR和AT。R可能均参与介导急性力竭运动引起心肌细胞凋亡的过程．

Study on expression Timing of Angiotensin II AT1 and AT2 Receptor After Acute Exhaustive Exercise in Rat Myocardium

Objective： To study the relation between the expression timing of angiotonin II receptor and exercise-induced apoptosis in myoeardium in rat. Methods- 40 healthy male SD rats are randomly divided into no-exercise group A（n：10）and exercise group B（n=30）. Rats run on the treadmill at speed of （252 2）m/min until exhaustion in group 13. After the exercise, animals were randomly grouped into animals killed 0hr（n： 10）, 6hr（n= 10） and 24hr（n= 10）. The expression of AIF mRNA was assessed by RT-PCR. Apoptosis Index was detected by the TUNEL technique in cardiac muscle. AT1 as well as AT2 receptor protein expression was assessed by Western blot. Results： To compare with control group, the expression of AIF mRNA were increased 6.69（ P 〈0. 05）,9. 32（ P 〈0.05） 和 10.82 times（ P 〈0. 001） respectively postexercise 0,6 and 24 h. Apoptosis Index were increased （17. 10± 3.6）% （ P 〈0. 001）, （33.3± 10.4）% （ P 〈0. 001）和 （ 30.7 ±2 9.2）% （ P 〈0. 001） respectively postexercise 0,6 and 24 h. AT1 receptor protein expression were increased 5.16%（ P 〉0.05） ,39.19%（ P 〈0. （35）和 64.44%（ P 〈0.05） ,and AT1 recep- tor protein expression were increased 2.15%（ P 〉0. 05）,10.12%（ P 〉0.05）和 28.30%（ P 〈0.05） re- spectively postexercise 0,6 and 24 h. Conclusion. The expression of ATIR and ATz R were increased sig- nificantly until postexercise 24 h. Angiotensin II receptors upregulated the expression of AIF mRNA after acute exhausitive exercise. AT1 R and AT2 R could play a role in mediated apoptosis in cardiomyocytes af- ter excessive exercise.