Xu Zhen-dong, Shi Xue-yin, He Xing-ying, Liu Gang, Ye Tian-wen
Department of Anesthesiology, Changzheng Hospital, The Second Military Medical University, Shanghai 200003, China.
Zhongguo Wei Zhong Bing Ji Jiu Yi Xue. 2005 Jan;17(1):57-9.
To study the effects of high level spinal cord injury (SCI) on rat heart, and investigate the role of endothelin-1 (ET-1) in the harmful effects on heart after SCI.
Forty-eight male SD rats were randomly divided into six groups of 8 animals each: control group; 4-hour group: 4 th hour after injury to spinal cord at cervical 7 level; 12-hour group: 12 th hour after injury to 7 spinal cord at C7 level; 24-hour group with same injury; 48-hour group and 72-hour group, all with same injury. Mean arterial pressure (MAP), heart rate (HR), left ventricle systolic pressure (LVSP), and left ventricular maximum velocities of contraction (+/-dp/dt max) were recorded in each group. Lactate dehydrogenase (LDH), creatine kinase (CK), MB isoenzyme of creatine kinase (CK-MB) and ET-1 contents in the myocardium. were also measured. Specimens of the myocardium were harvested for ultrastructure examination with transmission electron microscopy.
Hemodynamics variables including HR, MAP, LVSP and+/-dp/dtmax were significantly decreased in all the injury groups compared with that of control group (P<0.05 or P<0.01). These variables in 12-hour group showed lowest values among all the groups (all P<0.01). But the values of cardiac enzymes were much higher in five injury groups compared with that of control group (P<0.05 or P<0.01). ET-1 contents in serum and cardiac tissue raised markedly after the injury was inflicted to the animals (P<0.05), reaching peak at 12 hours (P<0.01). Ultrastructural examination of the myocardial tissue demonstrated that there were mild dissolution of myocardial fibrils and vacuolation of mitochondria at 12 hours after injury.
High level SCI could induce myocardial injuries and an excessive production of ET-1 in circulation and myocardial tissue might play a role in myocardial damage after injury of the spinal cord at a high level.
研究高位脊髓损伤（SCI）对大鼠心脏的影响，并探讨内皮素-1（ET-1）在SCI后心脏损伤中的作用。
48只雄性SD大鼠随机分为6组，每组8只：对照组；4小时组：颈7水平脊髓损伤后第4小时；12小时组：颈7水平脊髓损伤后第12小时；24小时组：同样损伤后24小时；48小时组和72小时组：同样损伤后48小时和72小时。记录每组的平均动脉压（MAP）、心率（HR）、左心室收缩压（LVSP）和左心室最大收缩速度（±dp/dt max）。同时检测心肌中的乳酸脱氢酶（LDH）、肌酸激酶（CK）、肌酸激酶MB同工酶（CK-MB）和ET-1含量。取心肌标本用透射电子显微镜进行超微结构检查。
与对照组相比，所有损伤组的血流动力学指标包括HR、MAP、LVSP和±dp/dt max均显著降低（P<0.05或P<0.01）。12小时组的这些指标在所有组中最低（均P<0.01）。但5个损伤组的心肌酶值均显著高于对照组（P<0.05或P<0.01）。动物受伤后血清和心脏组织中的ET-1含量明显升高（P<0.05），在12小时达到峰值（P<0.01）。心肌组织超微结构检查显示，损伤后12小时心肌纤维轻度溶解，线粒体空泡化。
高位SCI可导致心肌损伤，循环和心肌组织中ET-1的过度产生可能在高位脊髓损伤后心肌损伤中起作用。
