血红素氧合酶-一氧化碳系统对肝硬化大鼠血流动力学的影响

目的 观察血红素氧合酶-一氧化碳系统对肝硬化大鼠全身血流动力学的影响.方法将30只雄性SD大鼠分为对照组(14只)和肝硬化组(16只),肝硬化组大鼠皮下注射50%四氯化碳(以橄榄油稀释,0.003 ml/g),对照组给予相同剂量的橄榄油.12周后,将肝硬化组大鼠分为肝硬化给药组(8只)、肝硬化模型组(8只),对照组大鼠分为正常给药组(7只)、正常对照组(7只).肝硬化给药组和正常给药组大鼠经后颈部皮下注射锌原卟啉(20 μmol/kg),肝硬化模型组和正常对照组予以等渗盐水,用动脉插管生理多导仪记录心率、平均动脉压的变化,门静脉插管测定门静脉压,联二亚硫酸盐还原法测定血浆一氧化碳水平,用比色法测定胆红素生成量.数据间比较用t检验.结果 正常对照组与肝硬化模型组大鼠平均动脉压分别为(18.9±0.9)kPa和(15.6±1.7)kPa,门静脉压分别为(8.8±0.3)cm H2O(1 cm H2O=0.098 kPa)和(16.7±0.8)cm H2O,血浆一氧化碳分别为(10.4±1.3)μmol/L和(18.0±1.9)μmol/L,脾脏血红素氧合酶(HO)活性分别为(6.5±0.9)nmol·mg1·h1和(11.1±0.9)nmol·mg 1·h-1,小肠HO活性分别为(1.3±0.2)nmol·mg1·h-1和(2.5±0.1)nmo1·mg-1·h-1,两组比较,t值分别为4.52、23.10、8.42、9.28、15.10,P值均＜0.01,差异有统计学意义.正常对照组与肝硬化模型组大鼠肝脏HO活性分别为(2.7±0.2)nmol·mg-1·h-1、(2.7±0.1)nmol·mg-1·h-1,差异无统计学意义.肝硬化模型组、肝硬化给药组平均动脉压分别为(15.6±1.7)kPa、(17.3±1.5)kPa,两组比较,t=2.18,P＜0.05,差异有统计学意义,门静脉压分别为(16.7±0.8)cmH2O、(13.2±0.7)cmH2O,两组比较,t=8.53,P＜0.01,差异有统计学意义.结论 HO-CO系统的激活可能是肝硬化血流动力紊乱的重要原因.

Abstract：

Objective To investigate the role of heme oxygenase(HO), a catalyzing enzyme of heme to produce CO, in modulation of systemic circulation in CCl4-induced cirrhotic rats. Methods Saline (vehicle) and ZnPP were s.c. injected into the posterior necks of rats respectively and the rats were then anesthetized by pentobarbital sodium in four hours. Mean arterial pressure (MAP, kPa), heart rate (HR, b/min) and portal pressure (PP, cm/H2O) were measured by indwelling catheter. Plasma CO was determined by Chalmers method. Heme oxygenase acivity was determined by the rate of bilirubin formation. Results The cirrhotic rats showed significant hyperdynamic circulation indicated by decreased mean arterial pressure MAP,(15.6 ± 1.7) vs (18.9 ± 0.9) kPa, t = 4.52, P ＜ 0.01] and increased portal pressure PP, (16.7 ± 0.8)vs (8.8 ± 0.3) cm H2O, t = 23.10, P ＜ 0.01] as compared to normal control rats(NS). ZnPP could cause a significant increase in MAP (17.3 ± 1.5) vs (15.6 ± 1.7) kPa, t = 2.18, P ＜ 0.05] and significant decrease in PP (13.2 ± 0.7) vs (16.7 ± 0.8) cm H2O, t = 8.53, P ＜ 0.01] in cirrhotic rats. The cirrhotic group presented a significant increase in plasma CO (18.0 ± 1.9) vs (10.4 ± 1.3) μ mol/L, t = 8.42, P ＜ 0.01] and HO activity in the spleens (11.1 ± 0.9) vs (6.5 ± 0.9) nmol bilirubin/mg protein/h, t = 9.28, P ＜ 0.01 ] and intestines (2.5 ±0.1) vs. (1.3 ± 0.2) nmol bilirubin/mg protein/h, t = 15.1, P ＜ 0.01]. ZnPP could cause significant decreases in plasma CO and HO activity in liver, spleen and intestine of both control and cirrhotic rats. Conclusion HO-CO system activation may be an important reason for the hemodynamic disturbance of liver cirrhosis.

The role of HO-CO system in the hemodynamic disturbance of cirrhotic rats

Objective To investigate the role of heme oxygenase(HO), a catalyzing enzyme of heme to produce CO, in modulation of systemic circulation in CCl4-induced cirrhotic rats. Methods Saline (vehicle) and ZnPP were s.c. injected into the posterior necks of rats respectively and the rats were then anesthetized by pentobarbital sodium in four hours. Mean arterial pressure (MAP, kPa), heart rate (HR, b/min) and portal pressure (PP, cm/H2O) were measured by indwelling catheter. Plasma CO was determined by Chalmers method. Heme oxygenase acivity was determined by the rate of bilirubin formation. Results The cirrhotic rats showed significant hyperdynamic circulation indicated by decreased mean arterial pressure MAP,(15.6 ± 1.7) vs (18.9 ± 0.9) kPa, t = 4.52, P ＜ 0.01] and increased portal pressure PP, (16.7 ± 0.8)vs (8.8 ± 0.3) cm H2O, t = 23.10, P ＜ 0.01] as compared to normal control rats(NS). ZnPP could cause a significant increase in MAP (17.3 ± 1.5) vs (15.6 ± 1.7) kPa, t = 2.18, P ＜ 0.05] and significant decrease in PP (13.2 ± 0.7) vs (16.7 ± 0.8) cm H2O, t = 8.53, P ＜ 0.01] in cirrhotic rats. The cirrhotic group presented a significant increase in plasma CO (18.0 ± 1.9) vs (10.4 ± 1.3) μ mol/L, t = 8.42, P ＜ 0.01] and HO activity in the spleens (11.1 ± 0.9) vs (6.5 ± 0.9) nmol bilirubin/mg protein/h, t = 9.28, P ＜ 0.01 ] and intestines (2.5 ±0.1) vs. (1.3 ± 0.2) nmol bilirubin/mg protein/h, t = 15.1, P ＜ 0.01]. ZnPP could cause significant decreases in plasma CO and HO activity in liver, spleen and intestine of both control and cirrhotic rats. Conclusion HO-CO system activation may be an important reason for the hemodynamic disturbance of liver cirrhosis.