慢性低氧对大鼠左右心室的功能及TRPC亚家族表达的影响  

Effects of chronic hypoxia on left and right ventricular function and the expression of cardiac TRPC channels in rats

作　　者：陈慧勤[1] 林默君[2] 刘晓如[2] 

机构地区：[1]泉州医学高等专科学校基础医学部,福建泉州362011 [2]福建医科大学基础医学院生理学与病理生理学系,福州350108

出　　处：《中国应用生理学杂志》2014年第3期274-278,I0003,共6页Chinese Journal of Applied Physiology

基　　金：国家自然科学基金资助项目(31171104);福建省重点建设高校重大科研项目(09ZD010)

摘　　要：目的:探讨慢性低氧3周对大鼠左右心室的影响以及规范性瞬时感受器电位亚家族(TRPC)在慢性低氧诱导的右心室心肌肥厚中的表达。方法:将SD雄性大鼠48只随机分为对照组(CON组)和慢性低氧肺动脉高压模型组(CH组)(n=24),CH组将大鼠置于连续的慢性低氧(10%±0.2%)环境饲养三周以诱导大鼠发生心肌肥厚。通过左、右心室插管法测定右心室内压(RVSP)、左心室内压(LVSP)、心率(HR)、平均体循环动脉压(mSAP)、左、右心室内压力最大上升速率(+dp/dtmax)、最大下降速率(-dp/dtmax)、右心肥大指数(RVMI)、左心肥大指数(LVMI);HE染色观察左、右心室心肌组织切片;通过SYBR Green荧光定量PCR法检测CON组、CH组大鼠的肥厚侧心室心肌组织编码TRPC1/3/4/5/6/7的mRNA表达;结合real-time RT-PCR结果对mRNA表达有显著变化的TRPC亚型通过免疫印迹法检测相应蛋白的表达。结果:与CON组相比:CH组的RVSP、RVMI、右心室±dp/dtmax显著增高(P<0.01),LVSP、左心室±dp/dtmax无显著变化,LVMI显著降低(P<0.01);CH组右心室心肌细胞显著增粗(P<0.01),细胞内肌原纤维数量增多,心肌纤维排列紊乱,细胞核深染,形状不整;左心室心肌纤维无明显改变;CH组编码TRPC1的mRNA和蛋白显著增高(P<0.05),而编码其余TRPC亚型的mRNA无显著变化。结论:慢性低氧3周可特异性诱导SD大鼠产生右心室心肌肥厚,上调了编码右心室心肌细胞TRPC1通道蛋白的mRNA和蛋白的表达,TRPC1可能参与了心肌肥厚的发生发展。Objective： To explore the effects of chronic hypoxia on left and right ventricular function and the expression of cardiac transient receptor potential canonical （TRPC） channels in rats. Methods： Forty eight SD male rats were randomly divided into control group （CON） and chronic hypoxic pulmonary hypertension model group （CH） （ n = 24）. In CH group, rats were exposed in chronic hypoxia envirenment（10% ± 0.2% 02） to induce myocardial hypertrophy. After 3 weeks, mean systemic arterial pressure（mSAP）, right ventricular systolic pressure （RVSP）, left ventricular systolic pressure （LVSP）, left or right ventricular pressure maximum rate of rise （LV/RV ＋ dp/dtm=）, left or right ventricular pressure maximum rate of descent （LV/RV-dp/dtmax）, right ventricular hypertrophy index （RVMI） and left ventricular hypertrophy index （LVMI） were measured. Left and right ventricular myocardium tissue sections were stained by HE and observed under light microscope. Real-time polymerase chain reaction （real-time-PCR） and Western blot were performed to detect the expression of TRPC subfamily. Results ： RVSP, RVMI, RV ＋ dp/dtmax and RV-dp/dtmax, were markedly elevated in CH group （ P 〈 0.01 ） in comparison to CON group. LVMI was markedly reduced in CH group in comparison to CON group （ P 〈 0.01）. LVSP, LV ＋ dp/dtmax and LV- dp/dtmax had no significant changes in CH group in comparison to CON group. Right ventricular myocardial cells of CH group became thick, the nuclei stained deeply, the shape of nuclei became not regularity. Left ventricular myocardial fibers did not change significantly. There was significant difference in the levels of mRNA and protein of TRPCl between CON and CH groups. Conclusion： For three weeks exposed to chronic hypoxia induced right ventricular hypertrophy specifically, raised the mRNA and protein expression of TRPC1 on right ventricular myocardial cells. TRPC1 might be involved in the development of cardiac hypertrophy.

关 键 词：低氧 规范性瞬时感受器电位 心肌肥厚 CA2+ 

分 类 号：R363[医药卫生—病理学]