摘要
目的探讨犬急性心肌梗死早期行冠状动脉旁路移植术(CABG)对梗死周边区心肌神经纤维密度的影响及意义。方法结扎犬冠状动脉前降支制备心肌梗死模型(30只)。分别在心肌梗死后第1、2、4和6周行CABG作为实验组,其中第2周4只,其余各组6只;分别为每个实验组设立未行CABG的心肌梗死对照组,每组2只。CABG术8周后开胸切取心脏,分别切取每只犬的梗死周边区作为实验组样本,并取未结扎冠状动脉相应区域的心肌组织作为空白对照组。采用免疫组化方法检测样本的生长相关蛋白43(GAP-43)、酪氨酸羟化酶(TH)的表达。应用Metamorph UIC(US)软件及Olympus/Evolution MP 5.0/BX51(JP)显微镜组成的计算机图像处理系统定量测定神经纤维密度。结果心肌梗死对照组GAP-43表达水平明显高于空白对照组和实验组[心肌梗死对照组:(1333.3±169.1)μm2/mm2;空白对照组:(625.4±121.7)μm2/mm2;实验组:第1、2、4和6周行CABG实验组:(656.9±147.5)μm2/mm2、(683.0±157.2)μm2/mm2、(737.0±158.3)μm2/mm2和(847.8±169.4)μm2/mm2,P<0.01];心肌梗死对照组的TH表达水平明显高于空白对照组和实验组[心肌梗死对照组:(1082.0±114.3)μm2/mm2;空白对照组:(435.7±106.9)μm2/mm2;第1、2、4和6周行CABG实验组:(440.2±105.2)μm2/mm2、(484.0±112.2)μm2/mm2、(521.8±100.1)μm2/mm2和(692.4±117.1)μm2/mm2,P<0.01],其中第6周行CABG实验组的TH表达水平明显高于空白对照组及其他时间行CABG实验组(均为P<0.05);心肌梗死对照组及第6周行CABG实验组的TH/GAP-43明显高于空白对照组和其他时间行CABG实验组(心肌梗死对照组:81%±2%;空白对照组:69%±6%;第1、2、4和6周行CABG实验组:67%±4%、71%±4%、71%±7%和82%±2%,P<0.05)。结论犬急性心肌梗死早期行CABG可以减少梗死周边区心肌中神经纤维密度,尤其是4周内行CABG可以减轻梗死周边区心肌交感神经重构。
Objective To investigate the effect and significance of early coronary artery bypass graft （CABG） to the distribution and densities of neurofilament at infarcted border zone （IBZ） of dog with acute myocardial infarction （AMI）. Methods Thirty dogs were randomly assigned into experimental group （ n = 22） and control group （n = 8 ）, and AMI model were made by ligating left anterior descending coronary. Dogs in experimental group accepted CABG after 1 week （ n = 6 ） , 2 weeks （ n = 4 ） , 4 weeks （ n = 6 ） or 6 weeks （ n = 6） after AMI and dogs in control group were not underwent CABG. The distribution and densities of growth associated protein 43 （GAP43） and tyrosiue hydroxylase （TH） positive nerves at IBZ were detected by immunohistochemical techniques through thoracotomy at eight weeks after CABG. Nerve fiber density was determined by Metamorph UIC （US） software and Olympus/Evolution MP 5.0/BX5I （JP） microscope image processing system. Results The densities of GAP43 at IBZ in control group were significantly higher than those in experimental group and normal heart tissue [ control group： （1333.3±169. 1 ）μm^2/mm^2 ; normal heart tissue： （625.4 ±121.7 ）μm^2/mm^2 ; experimental group： （ 656. 9± 147.5）μm^2/mm^2 for CABG after 1 week, （683.0 ± 157.2） μm^2/mm^2 for CABG after 2 weeks, （737. 0 ± 158.3） μm^2/mm^2 for CABG after 4 weeks, （847.8 ＋ 169.4） μm^2/mm^2 for CABG after 6 weeks, all P 〈 0. 01 ]. Also the expression level of TH at IBZ in control group was significantly higher than those in experimental group and normal heart tissue [ control group： （1082. 0 ±114. 3 ） μm^2/mm^2 ; normal heart tissue ： （435.7 ± 106. 9 ） μm^2/mm^2 ; experimental group ： （440. 2 ± 105.2 ）μm^2/mm^2 for CABG after 1 week, （484. 0 ±112. 2） μm^2/mm^2for CABG after 2 weeks, （521.8± 100. 1 ） ixm2/mm2 for CABG after 4 weeks, （692.4± 117.1 ）μm^2/mm^2 for CABG after 6 weeks, all P 〈0.01 ]. The densities of TH in dogs accepted CABG after 6 weeks after AMI were significantly higher than those in other experimental groups and normal heart tissue （ P 〈 0. 05 ）. TH/GAP43 （ % ） of dogs accepted CABG after 6 weeks after AM! and control group were significantly higher than those of other experimental groups and normal heart tissue （control group：81%± 2%; normal heart tissue： 69% ±6%; experimental group： 67%± 4% for CABG after 1 week, 71% ±4% for CABG after 2 weeks, 71% ±7% for CABG after 4 weeks, 82%±% for CABG after 6 weeks, all P 〈 0. 05）. Conclusions Early CABG especially within 4 weeks may lessen the densities of nerve and the remodeling of sympathetic nerve at IBZ in dog with AMI.
出处
《中国心血管杂志》
2012年第1期38-42,共5页
Chinese Journal of Cardiovascular Medicine
关键词
心肌梗死
交感神经
心律失常
Myocardial infarction
Sympathetic nerve
Coronary artery bypass graft
作者简介
通讯作者：谷天祥，电子信箱：zhangdaya127@yahoo．com.cn
