兔陈旧性心肌梗死心室肌中神经纤维的形态学变化及增生对室颤阈值的影响  

Morphology of nerve fibers and the effect of nerve proliferation on ventricular fibrillation threshold in rabbit ventricle with healed myocardial infarction

作　　者：刘念[1] 牛惠燕[1] 周强[1] 阮燕菲[1] 卜军[1] 李泱[1] 张存泰[1] 陆再英 

机构地区：[1]华中科技大学同济医学院附属同济医院心内科,武汉430030

出　　处：《中华心血管病杂志》2004年第6期504-507,共4页Chinese Journal of Cardiology

摘　　要：目的　研究神经纤维在兔陈旧性心肌梗死 (HMI)心室肌中的分布及形态学改变 ,并观察HMI兔中神经纤维的过度增生对室颤阈值的影响 ,为阐明自主神经在HMI心律失常和猝死中的作用提供实验依据。方法　 30只兔随机分为三组 :( 1)HMI组结扎冠状动脉左回旋支 ;( 2 )神经生长因子组结扎左回旋支并通过颈部皮下置管于左侧星状神经节 ,给予神经生长因子 4 0 0U× 30d ;( 3)假手术组开胸但不结扎冠状动脉和皮下置管。 3个月后三组动物均进行室颤阈值测定 ,免疫组化法研究兔心室肌中S 10 0蛋白和酪胺酸羟化酶 (TH)的分布和密度。结果　假手术组心室肌中的神经纤维呈非均态分布 ,HMI组心室肌神经分布紊乱。HMI组存在神经纤维再生和增生 ,特别是梗死周边区 ,具有特殊的表型 ,以TH阳性染色为主。神经生长因子组神经纤维密度明显较假手术组和HMI组增高 (P <0 0 5 ) ,其室颤阈值为 ( 7 0 0± 1 0 4 )V ,较HMI组和假手术组的 ( 9 16± 1 2 3)V和( 13 31± 2 12 )V明显降低 (P <0 0 5 )。结论　HMI心室肌中神经分布紊乱 ,存在神经再生和增生 ,以TH阳性染色为主 ,心肌梗死后过度的神经纤维增生可进一步促进梗死心脏的电不稳定性。Objective To investigate the distribution and morphology of nerve fibers in rabbit heart with healed myocardial infarction(HMI) and the effect of excess nerve proliferation in rabbit with HMI on ventricular fibrillation threshold so as to provide experimental data for the effects of autonomic nerve system on arrhythmia and sudden death in HMI. Methods Thirty rabbits were randomly assigned three groups: HMI group, ligation of the circumflex coronary; NGF group, ligation of the circumflex coronary and polyethylene pipe placed to left satellite ganglion in subcutis of neck for administration of nerve growth factor(NGF) 400 U×30 d; sham group, thoracotomy but no conorary ligation and without subcutaneous polyethylene pipe. Three months after operation, ventricular fibrillation threshold(VFT) was measured and the distribution and density of S 100 protein and tyrosine hydroxylase(TH) in ventricle were detected with immunohistochemical technique. Results The distribution of nerve fibers in ventricle of sham group was inhomogeneous, which became more chaotic in HMI group. There were nerve regeneration and proliferation in HMI group, especially in infracted border zone, where the nerve fibers possessed special modality and was immunoreactive to TH mainly. The nerve fibers density in NGF group was higher than those in sham group and HMI group( P <0 05).VFT of NGF group was (7 00±1 04) V, which decreased significantly compared with those of HMI group and sham group, (9 16±1 23) V and (13 31±2 12) V respectively( P <0 05). Conclusion The distribution of nerve fibers in ventricle of HMI group was chaotic. There were regeneration and proliferation of nerve fibers in HMI group, which were immunoreactive to TH mainly. Excess nerve proliferation might facilitate the electrical unsteadiness in healed myocardial infarction further.

关 键 词：兔 陈旧性心肌梗死 心室肌 神经纤维 形态学 增生 室颤阈值 

分 类 号：R542.22[医药卫生—心血管疾病]