摘要
目的研究内毒素(脂多糖,LPS)对野生型小鼠心肌细胞钙火花和钙瞬变以及t小管结构的作用,探讨内毒素致心脏损害的可能机制。方法 C57BL/6雄性小鼠,分离心脏后Langendorff灌流法获取心室肌细胞。Fluo-4/AM钙荧光指示剂负载细胞,应用激光共聚焦显微镜成像技术记录10μg/ml LPS灌流30 min前后心肌细胞的钙信号(钙火花和钙瞬变)变化,测定钙火花幅度、空间大小、时程、频率变化以及钙瞬变幅度、达峰时间和衰减时间。同法分离心室肌细胞做细胞培养,给药组给予10μg/ml LPS,对照组给予灭菌注射用水,24及48 h取培养细胞,Di-8ANEPPS膜荧光指示剂负载细胞,应用激光共聚焦显微镜成像技术记录心肌细胞t小管结构变化。结果 LPS灌流可明显增加钙火花频率(0.68±0.1 vs 0.20±0.04 events/100μm/s,P<0.001),对钙瞬变无明显影响。给药组48h后较对照组t小管结构有轻微破坏(1.47±0.04 vs 1.60±0.05,P=0.04)。结论内毒素可引起小鼠心室肌细胞钙火花频率增大,后期t-小管结构破坏。
Objective To investigate how lipopolysaccharide （LPS） affect Ca2~ signal and t-tubule structure in wild type mice ventrieular myoeytes, and explore the potential mechanism of LPS induced cardiotoxicity. Metheds Veutricu- lar myocytes of C57BL/6 male mice were isolated through Langendorff perfusion. Laser confoeal microscopy was used to measure Ca2＋ spark frequency （CaSpF） and Ca2＋ transient of the isolated myocytes before and after 10ug/ml LPS perfusion. The F/F0, full duration at half maximum, full width at half maximum, frequency of Ca2＋ sparks and the F/F0, Tpeak, T50, 390 of Ca2＋ transient were measured. The Ca2＋ signal was determined by using Flu4/AM. T-tubules of cultured ven- tficular myocytes （24 b and 48 h） in 10 μg/m LPS treatment and saline groups were recorded by Laser confocal microsco- py. T-tubule structure was determined by Di-8 ANEPPS. Results CaSpF was significantly increased in WT mice ven- tricular myocytes after 10 μg/ml LPS perfusion（0. 68±0.1 vs 0. 200.04 events/100μm/s, P〈0. 001 ） but there was no significant change in Ca2＋ transient. LPS stimulated t-tubule remodeling in 48 h cultured cell although the damage was mild （1.47±0.04 vs 1.60±0.05, P= 0. 04 ）. Conclusion LPS induced WT mice CaSpF significantly and damage t-tubule structure mildly, which might stimulate arrhythmia in sepsis.
出处
《中国心脏起搏与心电生理杂志》
2013年第2期155-158,共4页
Chinese Journal of Cardiac Pacing and Electrophysiology
关键词
心血管病学
内毒素
钙火花
t小管
心肌损害
Cardiology
Lipopolysaccharide
Ca2＋ spark
T-tubule
Cardiotoxicity
