摘要
目的 研究严重烧伤早期大鼠心脏交感神经电生理活动的变化规律及其机制 ,探讨心脏交感神经活动的变化与严重烧伤后心脏损伤的关系。 方法 SD大鼠随机分为正常组 (6只 )、假伤组 (18只 )和烧伤组 (2 0只 ) ,在烧伤组大鼠背部制成 30 %TBSA的Ⅲ度烫伤。应用神经电生理方法记录心脏交感神经的放电活动 ,同时观察心电图和心肌力学指标的变化。 结果 严重烧伤后大鼠心脏交感神经传出活动即刻增强 ,而传入活动经一潜伏期 (约 90s)后也显著增强 ,且传入活动增强后传出活动进一步增强。交感神经传出、传入活动增强约持续 3h左右 ,而后显著降低 ,传入活动的变化早于传出活动的变化。部分大鼠在烧伤后 1h左右 ,心脏交感神经放电活动除平均值增加外 ,波动性增大 ,呈间歇性“爆发”现象 ,其中 4只大鼠在放电爆发性增加的同时频发室性早搏。烧伤后左心室收缩压峰值和左室内压最大上升 /下降速率显著降低。 结论 严重烧伤后早期心脏交感神经传入和传出活动均增强 ,且传入活动的变化对传出活动的变化有一定的影响。心脏交感神经电生理活动增强可能是严重烧伤后早期心脏损伤的原因之一。
Objective To investigate the mechanism and the rule of the change in cardiac sympathetic neuroelectrop hysiology in severely scalded rats during early postburn stage,so as to explore the relationship between the change and postburn severe cardiac injury. Methods Forty-four Sprague-Dawley rats were randomly divided i nto normal(n=6),sham injury (n=8) and scalded(n=20) groups.The rats in scalded g roup were inflicted by 30%TBSAⅢ degree burn on the backs.The electric discharg e activity of cardiac sympathetic nerve was observed and recorded by neuroclectr ophysiological technique.The changes in ECG and myocardial mechanic indices were simultaneously observed. Results The activity of efferent cardiac sympathetic ne rve incre ased immediately after scalding,but that of the afferent nerve increased obviou sly after about 90 s incubation period.The activity of efferent nerve f urther increased afer the increase of afferent activity,and this increase in both efferent and afferent nerves lasted for about 3 hours and decreased evi dently thereafter.The change of afferent nerve was earlier than that of efferent nerve.The average electric discharge activity of cardiac sympathetic nerve incr eased with obvious fluctuation,which exhibited intermittent burst pattern at 1 PBH in some rats,in which frequent ventricular extrasystole appeared accompanyin g with the simultaneous increase in electric discharge burst in 4 rats. The postburn LVDP and ±dp/dtmax in rats decreased significantly. Conclusion The activities of both efferent and afferent cardiac sympathetic nerve increased dramatically in the early postburn stage.Th e change in efferent nerve activity could be affected to some de gree by that of afferent nerve.This implied that the increase of the neuroelectr ophysiological activity of cardiac sympathetic nerve might be one of the causes of early severe postburn cardiac injury.
出处
《中华烧伤杂志》
CAS
CSCD
2001年第5期272-275,共4页
Chinese Journal of Burns
关键词
烧伤
交感神经
电生理
心肌力学
Burn
Sympathetic nerve
Electrophysiology
M yocardial mechanics
