内皮素和一氧化氮在烧伤后肝脏血流调节中的作用

目的：研究内皮素（ＥＴ）和一氧化氮（ＮＯ）在烧伤后肝脏血流调节中的作用。方法：动态观察大鼠３０％Ⅲ度烧伤后血浆及肝脏ＥＴ、ＮＯ含量及肝脏血流量的变化，应用ＥＴ受体拮抗剂和外源性ＮＯ载体观察其对烧伤大鼠肝脏血流量的影响。结果：大鼠烧伤后肝脏血流量明显下降，伤后血浆及肝组织ＥＴ和ＮＯ含量明显升高，由于ＥＴ升高幅度相对较大，ＥＴ／ＮＯ比值也显著增加，肝组织ＥＴ、ＥＴ／ＮＯ改变与肝脏血流量的降低呈显著负相关；伤后在一定的液体复苏下应用两种ＥＴ受体拮抗剂和ＮＯ供体在一定程度上明显使肝血流量增加，同时拮抗ＥＴ受体Ａ（ＥＴＡ）、ＥＴ受体Ｂ（ＥＴＢ）较单独拮抗ＥＴＡ效果好，ＥＴ受体拮抗剂和ＮＯ供体配合使用效果更佳。结论：烧伤后由于肝脏ＥＴ的增加和内源性ＮＯ相对不足，导致肝脏血管收缩造成肝脏血流量下降，拮抗ＥＴ的作用和（或）补充外源性ＮＯ则可一定程度逆转烧伤后肝脏血流量下降

The significance of endothelin and nitric oxide in the regulation of hepatic blood flow in burned rats

Objective :To elucidate the significance of endothelin (ET) and nitric oxide (NO) in the regulation of hepatic blood flow in burned rats. Methods :Using a 30% total body surface area degree burned rat model,dynamic changes in ET and NO contents as well as hepatic blood flow were determined both in plasma and liver tissue postburn.Meanwhile,the effects of ET receptor antagonists and NO donor on hepatic blood flow in burned rats were observed. Results :The hepatic blood flow decreased sharply in burned rats,accompanied by increases in ET and NO in plasma and liver tissue.The ratio of ET/NO in liver elevated significantly.Changes in ET and ET/NO ratio were significantly correlated with hepatic blood flow.Administration of ET receptor antagonists (PD147953,PD145065) and NO donor (SIN 1) was demonstrated to be able to reverse the decrease in hepatic blood flow postburn.Furthermore,better outcome could be achieved by blocking both ET receptors than by interfering with only ETA,and even much better result could be anticipated if NO donor was given together. Conclusions :The pathological alterations in ET and NO may contribute to the regulation of hepatic blood flow postburn.