N-乙酰半胱氨酸对肝损伤大鼠体内NO水平及NOS活性的影响

目的:探讨N-乙酰半胱氨酸(N-Acetylcysteine,NAC)对肝损伤大鼠肝脏病理的影响及对肝脏损伤保护的作用机制.方法:选用36只SD大鼠随机分为3组,正常对照组:腹腔注射生理盐水10ml/kg 1次;肝损伤模型组:给予D-gal 1g/kg腹腔注射1次;NAC实验组:于腹腔注射D-gal 1g/kg后6、12、18 h分别腹腔注射NAC 0.1mmol/kg 1次.急性肝损伤模型建立后24h取血及肝组织标本,观察比较各组大鼠肝组织病理改变,测定其血清、肝组织NO水平及肝组织NOS活性.结果:NAC实验组大鼠的肝脏病理形态较肝损伤模型组有所改善,其血清NO水平较肝损伤模型组增高,而肝组织中NO水平较模型组降低,均具有统计学差异.NAC组大鼠肝组织中cNOS活性较模型组有明显提高,而iNOS活性较模型组明显降低(P均＜0 05).结论:NAC可以改善急性肝损伤大鼠的肝脏病理改变,该保护作用可能通过影响不同型别的NOS活性而改变体内不同部位的NO水平有关.

The effect on nitric oxide and nitric oxide synthase of liver injured rat after N-acetylcysteine treatment

Objective:To evaluate the protective effect of NAC on the acute liver injury of rat and its mechanism.Methods:36 Sprague-Dawley (SD) rats were randomly divided into saline control group (group A,n=12), acute liver injury group (group B,n=12) and NAC intervention group (group C,n=12).In group B&C, SD rats were injected intraperitoneally with D-galactopyranoside(D-gal) (1g/kg). In group C, SD rats were received N-acetylcysteine (NAC) three times after D-gal were given.Animals were killed at 24 hours after the D-gal injection. The pathologic section of rat liver were observed and the concentration of NO and the activity of NOS in rat liver tissue of each group were assayed.Results:The pathologic changes of rat liver were significantly improved in NAC group. The hepatic NO concentration of acute liver injury rats were significantly decreased in the NAC group.Whereas the serum NO concentration was significantly increased in the same group.It showed that the iNOS were inhibited but the cNOS were activated after NAC treatment.Conclusion:NAC can improve the liver tissue pathologic changes of D-gal acute liver injury in rats. The protective activities may associate with the influence on the different types of NOS activities and then change the NO level in different organs in rats.