CAJ | 학술논문

目的研究慢性激活天门冬氨酸(N-methyl-d-aspartate,NMDA)受体对心室复极变异性和储备的影响,探讨其诱发室性心律失常的可能机制.方法 36只成年雄性Wistar大鼠分为:对照组(CTL组)、NMDA受体激动剂组(N组)和NMDA受体激动剂+抑制剂组(N+M组).在Langerdorff灌流下,行不同频率的S1S1和短阵快速(Burst)刺激左心室前壁和后壁;记录单向动作电位复极到90％的时限(MAPD90)的动态变化,计算短时限变异(STV)、电交替阈值和室性心律失常的诱发率.结果与CTL组相比,以不同周长刺激时,N组MAPD90和STV的动态变化幅度显著增大;诱发电交替的起搏周长显著增高[(111.67±2.97)ms对(88.33±2.41)ms,P＜0.01];刺激完成前的STV明显增大[(12.18±0.81)ms对(3.61±0.29)ms,P＜0.01];N组的室性心律失常诱发率和持续性室性心律失常比例均高于CTL组:S1S1模式:83.33％对25.00％,P=0.02和75.00％对8.33％,P＜0.01;Burst模式:100％对25％P＜0.01和83.33％对25.00％,P=0.02.N+M组的上述变化与CTL组相近,差异无统计学意义(P＞0.05).结论慢性激活NMDA受体明显增加室性心律失常的易感性,可能与心脏复极变异性增大和复极储备降低有关.
목적 연구만성격활천문동안산(N-methyl-d-aspartate,NMDA)수체대심실복겁변이성화저비적영향,탐토기유발실성심률실상적가능궤제.방법 36지성년웅성Wistar대서분위:대조조(CTL조)、NMDA수체격동제조(N조)화NMDA수체격동제+억제제조(N+M조).재Langerdorff관류하,행불동빈솔적S1S1화단진쾌속(Burst)자격좌심실전벽화후벽;기록단향동작전위복겁도90％적시한(MAPD90)적동태변화,계산단시한변이(STV)、전교체역치화실성심률실상적유발솔.결과 여CTL조상비,이불동주장자격시,N조MAPD90화STV적동태변화폭도현저증대;유발전교체적기박주장현저증고[(111.67±2.97)ms대(88.33±2.41)ms,P＜0.01];자격완성전적STV명현증대[(12.18±0.81)ms대(3.61±0.29)ms,P＜0.01];N조적실성심률실상유발솔화지속성실성심률실상비례균고우CTL조:S1S1모식:83.33％대25.00％,P=0.02화75.00％대8.33％,P＜0.01;Burst모식:100％대25％P＜0.01화83.33％대25.00％,P=0.02.N+M조적상술변화여CTL조상근,차이무통계학의의(P＞0.05).결론 만성격활NMDA수체명현증가실성심률실상적역감성,가능여심장복겁변이성증대화복겁저비강저유관.
Objective The purpose of this study was to investigate the effects of chronic N-methyl-d-aspartate receptors (NMDAR)activation on ventricular repolarization variability,reserves,and to explore the possible mechanisms of NMDAR induced ventricular arrhythmia.Methods A total 36 Wistar rats were randomly divided into control group(CTL group),NMDA group(N group) and NMDA+MK-801 group(N+M group).In Langerdroff-perfusedrat hearts,the S1 S1 and Burst stimulations were performed to construct the dynamic changes of monophasic action potential(MAPD),then calculating the short-term variability(STV),the threshold of alternans and inducibility of ventricular arrhythmias.Results Compared with the CTL group,the dynamic changes of MAPD90 and STV showed significantly increased in the N group at dynamic stimulus;the threshold of alternant was significantly increased(111.67±2.97)ms vs.(88.33±2.41)ms,P＜0.01.The STV before completion of stimulation significantly increased in the N group (12.18 ± 0.81) ms vs.(3.61 ± 0.29) ms,P＜0.01 ; the incidence of ventricular arrhythmias and the proportion of sustained ventricular arrhythmias were higher in the N group than that in the CTL group:S1 S1 model:83.33％ vs.25.00％,P=0.02 and 75.00％ vs.8.33％,P＜0.01 ;burst model:83.33％ vs.25.00％,P =0.02.The above electrophysiology alterations were not statistically significance in the N+M group compared with that in CTL group.Conclusion Chronic activation of NMDA receptors significantly increased the susceptibility to ventricular arrhythmias.This may be related with increased variability of cardiac repolarization and decreased repolarization reserve.