谷氨酰胺减轻离体大鼠心脏内毒素性损伤  

Protective effect of L-glutamine on myocardial cell injury in isolated rat heart induced by endotoxin

作　　者：戚仁斌[1] 陆大祥[1] 王华东[1] 王海华[2] 王彦平[1] 付咏梅[1] 

机构地区：[1]暨南大学医学院病理生理教研室,广东广州510632 [2]皖南医学院心血管功能研究所,安徽芜湖241001

出　　处：《基础医学与临床》2005年第6期498-502,共5页Basic and Clinical Medicine

基　　金：国家自然科学基金(30470718);广东省自然科学基金(04105844);广州市科技局重点项目(2004Z3-E4081)~~

摘　　要：目的研究谷氨酰胺抗大鼠离体心脏内毒素性损伤的作用。方法健康SD雄性大鼠24只,随机分成3组:正常对照组,内毒素组,谷氨酰胺+内毒素组,在Langendorff装置上用KH液对大鼠离体心脏行主动脉逆灌注。连续记录心肌细胞单相动作电位(MAP)、心肌收缩张力曲线;同时在相应的时点分别测定冠脉流出液中的一氧化氮(NO)含量、乳酸脱氢酶(LDH)和肌酸激酶(CK)的活性。结果谷氨酰胺可以减轻内毒素引起的心脏电活动的紊乱和收缩能力的损害,对内毒素引起的心肌细胞单相动作电位幅度减小及MAPD20延长、心肌张力降低、心率变慢等变化有明显的改善作用。谷氨酰胺对内毒素引起的冠脉流出液中一氧化氮含量的剧烈波动(先降低后快速升高)有明显的抑制作用,并且谷氨酰胺+内毒素组冠脉流出液中LDH和CK的活性明显低于内毒素组。结论谷氨酰胺可以对抗内毒素性心肌损伤、改善心功能状态,其机制可能与其抑制内毒素诱导的一氧化氮的剧烈波动、减轻心肌损伤有关。Objective To investigate the mechanism underlying protection of L-glutamine against myocardial injury of isolated rat heart induced by endotoxin. Methods Twenty-four male SD rats were randomly divided into three groups as control group(n=8),endotoxin group(n=8)and glutamine treatment group(n=8). Heart was isolated from rats and perfused on Langendorff apparatus with Krebs- Henseleit(KH)buffer(Saturation 95%+5% CO_ 2)at a constant pressure( 8.33 kPa)and temperature( 37 ℃). The levels of nitric oxide (NO),the activities of lactate dehydrogenase(LDH)and creatine kinase(CK)in efflux from coronary artery,monophasic action potential(MAP)and contractiale force were detected at 0 min, 20 min, 50 min, 80 min after L-glutamine and /or endotoxin perfusion. Results Monophasic action potential and contractile force were markedly improved in L-glutamine treatment group as compared to endotoxin group. The dramatically fluctuation of nitric oxide (NO) products induced by endotoxin was inhibited by L-glutamine. Furthermore,L-glutamine inhibited the increase of LDH and CK activities in efflux from coronary artery induced by endotoxin. Conclusion L-glutamine can protect the isolated rat heart against endotoxin-induced injury via inhibiti of fluctuation of nitric oxide (NO) production caused by endotoxin.

关 键 词：谷氨酰胺 内毒素性 离体大鼠心脏 LANGENDORFF 肌酸激酶(CK) 冠脉流出液 SD雄性大鼠 单相动作电位 心肌收缩张力 动作电位幅度 一氧化氮含量 离体心脏 心肌细胞 心肌损伤 正常对照组 乳酸脱氢酶 心脏电活动 心功能状态 

分 类 号：R96[医药卫生—药理学]