早期肠道喂养对烧伤大鼠肠道一氧化氮合酶的影响

目的阐明烧伤大鼠经早期肠道喂养后肠组织中一氧化氮合酶（ＮＯＳ）的变化规律及其与肠粘膜血流量（ＩＭＢＦ）的关系。方法采用３０％ＴＢＳＡⅢ度烧伤大鼠模型，分为正常对照（Ｃ）组，单纯烧伤（Ｂ）组和早期喂养（ＥＦ）组，分别检测伤前及伤后０，３，６，１２，２４，４８小时肠组织中ＮＯＳ活性，包括原生型ＮＯＳ（ｃＮＯＳ）和诱导型ＮＯＳ（ｉＮＯＳ），并测定肠粘膜血流量。结果烧伤后各组ｃＮＯＳ和ＩＭＢＦ呈下降趋势，二者呈显著正相关（ｒ＝０．９７，Ｐ＜０．０１），而ＮＯＳ总活性和ｉＮＯＳ活性都呈上升趋势，ＩＭＢＦ与ｉＮ－ＯＳ和总ＮＯＳ相关不显著。烧伤后ＥＦ组ｃＮＯＳ和ＩＭＢＦ明显高于Ｂ组，ｉＮＯＳ则低于Ｂ组，ＮＯＳ总活力两组无显著差异。结论①两型ＮＯＳ中ｃＮＯＳ与ＩＭＢＦ的关系更加密切。②早期肠道喂养改善烧伤后肠道缺血状况，可能与食物对肠壁神经的刺激从而提高ｃＮＯＳ活性有关。

Effects of early enteral feeding on nitric oxide synthase activity in small intestine in burned rat

\ Objective \ Our previous studies have proved that early enteral feeding could improve intestine blood flow after burn injury.But the mechanism was far from being clarified. This study was attempted to explore the effects of early enteral feeding on nitric oxide synthase(NOS) activity in burned rat small intestine and the relationship between the intestine mucosa blood flow (IMBF) and the activity of NOS.Methods\ The rats were randomly divided into three groups:burned control(B),burned and early enteral feeding(EF),and normal control(C).The activity of NOS including constitute NOS(cNOS) and inducible NOS(iNOS), and the IMBF were determined at postburn 0,3,6,12,24,48 hours.Results\ It was found that cNOS activity and IMBF were decreased markedly postburn,and there was positive correlation between cNOS and IMBF( r=0 97,P<0 01 ).But the activity of iNOS,total NOS were increased significantly postburn,they had no correlation to the IMBF.In EF group cNOS activity and the IMBF were significantly higher,the iNOS was obviously lower than that of B group and there was no significant difference of total activity of NOS between two groups.Conclusion\ Our results suggested that NOS which is catalyzed from cNOS may play main role in adjusting IMBF.By using early enteral feeding the activity of cNOS is increased and the ischemic state in small intestine is improved after burn injury.