超声联合微泡作用下即时产生非酶化一氧化氮的实验

Non-enzymatic nitric oxide induced by ultrasound mediated microbubble destruction

背景:一氧化氮是体内重要的气体信号分子,近年来研究发现一氧化氮可以在无一氧化氮合成酶存在的条件下合成,即非酶化一氧化氮合成,而非酶化途径合成一氧化氮,可能是许多生物学效应的机制之一。目的:观察超声联合微泡是否可以实现或者增效一氧化氮非酶途径的产生。方法:将L-精氨酸和H2O2按照1︰1,10︰1,10︰0.1,1︰10的比例混合,应用频率为1MHz,输出功率为0.5,1.0,1.5W/cm2的超声分别持续辐射60s,论证最优的L-精氨酸和H2O2的浓度比例以及最适的超声输出功率。确定最适浓度比和超声输出功率后,实验设立4组,分别进行超声联合微泡、单纯超声、微泡进行干预,空白对照组不进行干预,比较各组一氧化氮生成量。结果与结论:体外试验中,L-精氨酸和H2O2的浓度比例以10︰1为最佳,选择1.5W/cm2声强作为超声最优值。以此最适浓度比和超声输出功率干预,超声联合微泡组的一氧化氮生成量多于超声组(P<0.01);超声组一氧化氮生成量优于空白对照组(P<0.01);而微泡组的一氧化氮生成量与空白对照组没有差异。结果表明超声联合微泡可以增效一氧化氮的非酶合成。

BACKGROUND：Nitric oxide is one of the most important gas signaling molecule.Nitric oxide could be synthesized without nitric oxide synthetase,non-enzymatic nitric oxide,which might be one of the mechanisms of some biological effects.OBJECTIVE：To observe whether ultrasound mediated microbubbles could enhance the product by non-enzymatic pathway.METHODS：Laevo-arginine（L-Arg） was mixed with hydrogen peroxide（H2O2） by the concentration rates of 1：1,10：1,10：0.1,1：10,which were irradiated with ultrasound for 60 seconds（frequency：1 MHz,output power：0.5,1.0,1.5 W/cm2）.The optimal concentration of L-Arg and H2O2 and optimal output power of ultrasound were discussed and identified.This study set up four groups,and received respectively ultrasound mediated microbubbles,simple ultrasound and microbubbles.Blank control group did not receive any intervention.Formation amount of nitric oxide was compared among groups.RESULTS AND CONCLUSION：In vitro experiment,the optimal concentration ratio of L-Arg and H2O2 was 10：1,and 1.5 W/cm2 was the optimal ultrasound value.The content of nitric oxide was more in the ultrasound mediated microbubbles group than the simple ultrasound group（P 0.01）.The content of nitric oxide was better in the simple ultrasound group compared with blank control group（P 0.01）.No significant difference in the content of nitric oxide was detected between microbubble and blank control groups.Results suggested that ultrasound mediated microbubbles can enhance non-enzymatic synthesis of nitric oxide.