中性粒细胞介导的心肌缺氧再给氧损伤和L-精氨酸的保护作用

Effects of L arginine on Attenuating Neutrophil Mediated Damage to Isolated Myocytes after Anoxia and Reoxygenation

目的 探讨中性粒细胞对心肌复氧损伤的影响及L 精氨酸对中性粒细胞介导损伤的保护作用。方法 采用体外培养的乳鼠心肌细胞 ,72h后分 4组 :Ⅰ组单纯缺氧 5h ,再给氧 1 0h ;Ⅱ组在再给氧的同时加入中性粒细胞 ;Ⅲ、Ⅳ组在缺氧前分别先用 1、5mmol/L的L 精氨酸孵育 2h ,再行缺氧复氧。实验过程中在相差显微镜下观察细胞形态、搏动状况 ,各组在实验开始前、缺氧后和再给氧后抽取上清液 ,测LDH ,并在实验结束时计数各组的细胞存活率。结果 Ⅲ、Ⅳ组缺氧后LDH值明显低于Ⅰ、Ⅱ组 (分别为P <0 .0 5和 <0 .0 1 ) ;复氧后Ⅱ组LDH明显高于Ⅰ组 (P <0 .0 5 ) ,而Ⅲ、Ⅳ组则明显好于Ⅱ组 (P <0 .0 1 ) ;细胞存活率在Ⅱ组低于Ⅰ组 (P <0 .0 5 ) ,Ⅲ、Ⅳ组则明显较高 (与Ⅱ组相比P <0 .0 1 )。结论 中性粒细胞可通过多种机制加重心肌的再给氧损伤 ,而L 精氨酸可拮抗中性粒细胞的损伤 。

Purpose To assess the role of neutrophils in anoxia reoxyge nation induced damage on cardiac myocytes and the protection of L arginine against neutrophil mediated injury. Methods Neonatal rat beating cultured myocytes were divided into 4 groups.In group I cultured cells were exposed to a 5 h period of anoxia,and subsequently reoxygenated for 10 h.In group Ⅱ-Ⅳ neutrophils were added at the same time of reoxygenation.In group Ⅲ and group Ⅳ l and 5 mmol/L L arginine treated the cultured cells for 2 h before anoxia respectively.Myocytes injury was determined by release of lactate dehydrogenase (LDH). Results Compared to group Ⅰ,the release of LDH was obviously increased in group Ⅱ,the beating rates and survival rates of myocardial cells were lower.L arginine 1-5 mmol/L could increase the beating rates and survival rates of myocytes,and markedly decrease LDH releasing. Conclusions The results indicate that neutrophils could increase reoxygenation damage,while L arginine treatment could attenuate neutrophil mediated injury in cultured myocytes.