烧伤大鼠胃组织一氧化氮及一氧化氮合酶的变化

Alterations of nitric oxide synthase and nitric oxide in gastric tissues of burned rats

目的研究烧伤后胃组织中一氧化氮（ＮＯ）及两型一氧化氮合酶（ＮＯＳ）的变化规律．方法采用３０％ＴＢＳＡ（ｔｏｔａｌｂｏｄｙｓｕｒｆａｃｅａｒｅａ，ＴＢＳＡ）Ⅲ度烧伤大鼠模型（ｎ＝６４），分别检测伤后１，３，６，１２，２４，４８，７２ｈ胃组织中ＮＯ含量及原生型ＮＯＳ（ｃＮＯＳ）和诱导型ＮＯＳ（ｉＮＯＳ）的活性，并分析ＮＯ含量与两型ＮＯＳ活性之间的关系．结果烧伤后胃组织中ｉＮＯＳ活性与ＮＯ含量的变化趋势一致，伤后３ｈ即显著高于伤前，伤后１２ｈ达峰值，后有所下降但至伤后７２ｈ仍明显高于伤前，二者呈显著正相关（ｒ＝０９４，Ｐ＜００１）．而ｃＮＯＳ活性呈下降趋势，于伤后６ｈ达最低值，后渐回升于伤后７２ｈ基本恢复正常，ｃＮＯＳ与ＮＯ相关不显著（ｒ＝－０５４，Ｐ＞００５）．结论烧伤后胃组织中ＮＯ的变化主要受ｉＮＯＳ活性影响，而ｉＮＯＳ活性上升，ｃＮＯＳ活性下降可能与烧伤后胃的某些病理变化密切相关．

IM To investigate the regularity of changes of nitric oxide (NO) and two types of nitric oxide synthase (NOS) in gastric tissues after burn injury. METHODS Wistar rats (n=64) with 30% TBSA full thickness burns were used as models. The activity of inducible NOS(iNOS) and constitutes NOS (cNOS) as well as the content of NO in gastric tissues were determined at 1, 3, 6, 12, 24, 48 and 72 postburn hour (PBH). Meanwhile, the content of NO and the activity of two types of NOS were analysed by correlation analysis. RESULTS The NO content and iNOS activity showed a same tendency of flucturations. They were increased significantly at 3PBH, reached the peak level at 12PBH, then declined in the following 60 hours. There was a positive correlation between iNOS activity and the content of NO (r=094，P<001), while the cNOS activity was decreased remarkably, and reached the lowest level at 6PBH, then increased gradually and became normal at 72PBH. It has no correlation to the NO (r=-054，P>005).CONCLUSION The NO alterations in gastric tissues are mainly affected by iNOS activity. The activity changes of two types of NOS are related to some pathological changes of stomach after burn injury.