一氧化碳与肝硬化大鼠血脑屏障通透性的关系

目的 研究肝硬化大鼠血浆一氧化碳（ＣＯ）水平与血脑屏障通透性改变之间的关系。方法 将ＳＤ大鼠分为两组，ＣＣｌ４肝硬化模型组（ｎ＝１０）及正常对照组（ｎ＝１０），用联二亚硫酸盐还原法测定血浆ＣＯ的含量，用伊文思蓝法测定血脑屏障通透性，生理多导仪测定血压、心率等。结果 与对照组相比，肝硬化组血浆ＣＯ水平明显升高［（１８．３７±１．７９）μｍｏｌ／Ｌ ｖｓ （１０．２７±１．２１）μｍｏｌ／Ｌ，ｔ＝７．５，Ｐ＜０．０１］而平均动脉压（ｋＰａ）降低（１８．９３±０．７１　ｖｓ　１５．９２±０．７４），ｔ＝５．８３，Ｐ＜０．０１；血脑屏障通透性增加，脑内伊文思蓝含量肝硬化组明显高于对照组（１８．５２±１．３９ ｖｓ１５．０８±１．０６）ｎｇ／ｍｇ，ｔ＝３．９４，Ｐ＜０．０１。在肝硬化组血浆 ＣＯ水平与脑内伊文思蓝含量成正相关（ｒ＝０．７２，Ｐ ＜ ０．０１）而与平均动脉压成负相关（ｒ＝－０．６７，Ｐ＜０．０５）。结论 ＣＯ作为一种信使分子，不仅参与肝硬化大鼠低血压的发生，还与血脑屏障通透性增加有关，可能是肝硬化易诱发肝性脑病的重要介质之一。

Relationship between plasma carbon monoxide and blood-brain barrier permeability in cirrhotic rats

OBJECTIVE: To explore the relationship between plasma levels of carbon monoxide and blood-brain permeability in cirrhotic rats. METHODS: We measured mean arterial pressure (MAP), heart rate, plasma levels of carbon monoxide and amount of Evans blue in the brain tissue taken as the index of blood-brain permeability in cirrhotic rats (n=10) and controls (n=10). RESULTS: Cirrhotic rats showed significant increases in plasma carbon monoxide and amount of Evans blue in brain tissue compared with controls (18.37 +/- 1.79) micromol/L,(18.52 +.- 1.39) ng/mg vs (10.27 +/- 1.21) micromol/L, (15.08 +/- 1.06) ng/mg; P< 0.01]. Carbon monoxide levels in cirrhotic rats correlated positively with blood-brain barrier permeability and inversely with MAP (r=0.72, P< 0.01; r= -0.67, P< 0.05). CONCLUSIONS: Carbon monoxide, involving in the occurrence of hypotension and the increase of blood-brain barrier permeability, may play a role in the development of hepatic encephalopathy.