Effect of N~G-nitro-L-arginine on mitochondria in acute lung injury induced by LPS in rats

AIM:To examine the effect of nonselective nitric oxide synthase inhibitor,NG-nitro-L-arginine(L-NA),on mitochondria from acute lung injury induced by lipopolysaccharides(LPS)in rats.METHODS:The rats were randomly divided into control group,LPS injury group and L-NA treatment group.The model of acute lung injury was prepared with injection of LPS in rats.L-NA was respectively administrated through intraperitoneal injection at 3 h after injury induced by LPS.The rats were killed and the mitochondria in lung tissues were isolated by differential centrifugation.The activities of T-NOS,iNOS,ATPase,SOD and GSH-Px,and the contents of NO and MDA from mitochondria were respectively measured.The changes of ultrastructure in lung mitochondria were examined by electronic microscope after injury and L-NA treatment.RESULTS:The activities of T-NOS and iNOS were significantly increased,the activities of ATPase,SOD and GSH-Px were significantly decreased,the contents of NO and MDA were increased after acute lung injury.L-NA significantly enhanced the activities of ATPase,SOD and GSH-Px,and markedly decreased the contents of NO and MDA and the activities of T-NOS and iNOS.CONCLUSION:L-NA inhibits the activity of NOS in mitochondria,decreases the production of NO,improves mitochondria energy pump,ameliorates oxidative injury,and effectively protects lung tissue against acute lung injury induced by LPS.