一氧化氮合成酶抑制剂对大鼠液压脑创伤皮质血流的影响

目的探明一氧化氮（ＮＯ）在液压脑创伤后脑皮质血流改变中的作用。方法通过抑制一氧化氮合成酶（ＮＯＳ）活性以及给予ＮＯＳ底物使脑组织中产生ＮＯ的量增加或减少，来观察脑皮质血流对ＮＯ的反应。结果（１）ＮＯＳ抑制剂Ｌ－ＮＡＭＥ可致全身血压升高，并在一定剂量范围内呈剂量依赖性。（２）Ｌ－ＮＡＭＥ可使脑创伤皮质内的血流进一步下降。（３）Ｌ－ＮＡＭＥ可改变创伤后脑皮质血管的阻力反应性。结论ＮＯ在液压脑创伤后皮质血流调节中有重要作用，伤后早期即过度抑制ＮＯＳ活性，可致皮层血流进一步下降，加重神经损害。

Effects of L NAME on Cortical Regional Cerebral Blood Flow after Fluid Percussion Brain Injury in Rats

Aim To identify the role of nitric oxide in the changes of cortical regional cerebral blood flow (rCBF) after fluid percussion brain injury. Methods The action of nitric oxide products on rCBF was observed through inhibiting the nitric oxide synthase activity or increasing the substrate of nitric oxide synthase. Results (1) Inhibiting the nitric oxide synthase activity increased the whole blood pressure of the rats after fluid percussion brain injury and this action depended on the L NAME doses. (2)L NAME reduced the rCBF even more than that in the control group after fluid percussion brain injury. (3)The reactivity of small cortical vessels may be changed by L NAME. Conclusion Nitric oxide plays an important role in the regulation of rCBF. Inhibiting the activity of nitric oxide synthase can reduce the rCBF and deteriorate the nerve injury.