一氧化氮合酶抑制剂对严重烧伤大鼠的作用研究

目的 :研究一氧化氮合酶 (NOS)抑制剂对严重烧伤大鼠体内一氧化氮 (NO)含量及 NOS表达的影响及其与预后的关系。方法 :复制大鼠重症烧伤模型 ,检测应用非选择性 NOS抑制剂 N 硝基 L 精氨酸甲酯(L NAME)和选择性诱生型 NOS(i NOS)抑制剂氨基胍 (AG)后大鼠血液中 NO代谢产物 (NO- 2 /NO- 3 )以及肺和十二指肠组织中神经型 NOS(n NOS) m RNA的表达水平 ,同时统计各组大鼠的存活率。结果 :烧伤后大鼠血液中 NO- 2 /NO- 3 含量明显增高 ,L NAME和 AG都能抑制 NO2 /NO- 3 的升高 ,L NAME作用更为明显 ;烧伤后 n NOS的 m RNA表达在肺和十二指肠中均有不同程度升高 ,AG和 L NAME使 n NOS表达增加 ,AG作用更为明显 ;L NAME组动物存活时间较对照组显著缩短 ,AG组动物存活时间明显延长。结论 :结构型NOS(c NOS)与 i NOS在烧伤休克病理生理过程中的作用明显不同 ,i NOS活性过度增高与烧伤休克发病关系密切

The effect of nitric oxide synthase inhibitor on nitric o xide formation in rats after severe burns

Objective:To investigate the effects of nitric oxide synthase (NOS) inhibitor on nitric oxide(NO) production and expression of NOS in rats with severe burns.Methods:A rat model of severe burns was reproduced,the animals were treated with nonselective NOS inhibitor LNAME and selective inducible NOS (iNOS) inhibitor AG.Levels of NO - 2/NO - 3 in blood,mRNA expression of nerve NOS (nNOS) in lung and duodenum were determined,and survival time of animals in each group were also recorded.Results:Levels of NO - 2/NO - 3 in blood significantly increased postburn,which could be inhibited by LNAME and AG,especially by LNAME.Expression of nNOS mRNA in lung and duodenum increased postburn,which could be enhanced by AG and LNAME.Compared with the controls,survival time was remarkably shortened in LNAME group,while significantly prolonged in AG group.Conclusions:Constitute NOS (cNOS) and iNOS may play different role in the development of burn shock.The hyperactivation of iNOS appears to be closely associated with the initiation of burn shock.