一氧化氮在血管紧张素Ⅱ激活蛋白激酶C中的作用  

Influence of nitric oxide on the angiotensin Ⅱ-activated protein kinase C activity in cultured neonatal rat cardiomycytes

作　　者：符史干[1] 谢协驹[1] 吉丽敏[1] 刘培庆[2] 潘敬运[2] 鲁伟[2] 

机构地区：[1]海南医学院生理教研室,海口571101 [2]中山医科大学生理教研室,广州510089

出　　处：《生理学报》2003年第1期53-57,共5页Acta Physiologica Sinica

基　　金：ThisworkwassupportedbytheNaturalScienceFoundationofHainan (No 30 0 18)andthePublicHealthDepartmenofHainanProvince (No 琼卫 2 0 0 0 78)

摘　　要：实验在培养新生大鼠心肌细胞中检测NO前体L 精氨酸 (L Arg)和NO供体硝普钠 (SNP)对血管紧张素Ⅱ (AngⅡ )激活蛋白激酶C (PKC)的作用 ,以探讨心肌细胞PKC水平的信号转导途径。实验结果如下 :(1)无血清DMEM培养心肌细胞 2 4h后加入AngⅡ ,PKC活性呈剂量依赖性增高 ;(2 )培养基中加入L Arg ,PKC活性呈剂量依赖性降低 ;(3 )用L Arg 10 0 μmol/L进行预处理 ,3 0min后分别加入AngⅡ 0 1μmol/L或PMA 10μmol/L ,PKC活性均明显降低 ,与单纯AngⅡ组和单纯PMA组相比均有显著性差异 ;用NOS抑制剂L NAME预处理后 ,再加入L Arg ,可明显阻断L Arg对上述两个效应的影响 ;(4)培养液中加入NO供体SNP ,PKC活性呈剂量依赖性地降低 ;(5 )用SNP 10 μmol/L预处理心肌细胞 ,5min后分别加入AngⅡ或PMA ,PKC活性分别与单纯AngⅡ和单纯PMA组相比均明显降低。以上结果表明 ,AngⅡ能剂量依赖性激活PKC ,而NO可剂量依赖性抑制PKC活性 ;NOS参与L Arg抑制AngⅡ或PMA激活PKC的作用。这些观察提示 ,NO抑制AngⅡ对心肌细胞的作用可能是通过抑制PKC活性实现的 ,PKC可能是NO和AngⅡ在心肌细胞内信号转导的交汇点 (crosstalk)。We examined the effect of endogenous and exogenous nitric oxide (NO) on protein kinase C (PKC) activity induced by angiotensin Ⅱ (Ang Ⅱ) in cultured neonatal rat cardiomyocytes. The results are as follows. The activity of PKC was increased by AngⅡ (0 01～10 μmol/L) in a dose dependent manner, but decreased by NO precursor L arginine ( L Arg) (10 μmol/L～10 mmol/L) in a dose dependent manner in cultured neonatal rat cardiomyocytes. Pretreatment with L Arg (100 μmol/L) decreased significantly AngⅡ activated PKC activity and PKC activity induced by phorbol 12 myristate 13 acetate (PMA) ( 10 μmol/L), a PKC activator. Pretreatment with N G nitro L argingie methyl ester ( L NAME), a nitric oxide synthase (NOS) blocker, may inhibit significantly the role of L Arg on Ang Ⅱ and PMA activated PKC activity. The activity of PKC was also decreased by NO donor sodium nitroprusside (SNP) (10 μmol/L～1 mmol/L) in a dose dependent manner in cultured neonatal rat cardiomyocytes. Pretreatment with SNP (10 μmol/L) decreased significantly Ang Ⅱ and PMA activated PKC activity. These results indicate that PKC was controlled by both NO and Ang Ⅱ. PKC may be a 'cross talk' between Ang Ⅱ and NO in cardiomyocytes. NO abolished the activity of PKC and impaired PKC downstream signaling transduction pathway cascades.

关 键 词：心肌细胞培养 血管紧张素Ⅱ 一氧化氮 蛋白激酶C 

分 类 号：R33[医药卫生—人体生理学]