N eureg ulin-1对小鼠心室肌细胞钙瞬变的影响

摘要

Objective To observe the effects of neuregulin‐1 (NRG‐1)on calcium transients in mouse ventricular myo‐cytes.Methods Nine C57BL/6 mice of male were randomly dived into 3 groups :the blank control group ,NRG‐1 group ,and iso‐proterenol(ISO)group.Their hearts were removed and immediately cannulated via the aorta and retrogradely perfused with en‐zymatic isolation solution to get single ventricular cell by Langendorff system.Myocytes were loaded with the Ca2+ indicator Fluo‐4 and subjected to electrical field stimulation at 0.5 or 1 Hz by using living cells workstation.The change of fluorescene in‐tensity was recorded simultaneously in each group.Results Compared with the blank control group ,NRG‐1 group had signifi‐cantly increased Ca2+ transient amplitude ΔF/F0 (n=10 ,P<0.05) ,and reduced Ca2+ transient recovery time RT50 (n=10 ,P<0.05).There were no significant differences in Ca2+ transient amplitude ,Ca2+ transient recovery time and the time to peak be‐tween NRG‐1 and ISO groups(n=10 ,P>0.05).Conclusion NRG‐1 can increase Ca2+ transient amplitude and Ca2+ transients and reduce the time interval of Ca2+ transients.%目的：观察Neuregulin‐1（NRG‐1）对正常小鼠心室肌细胞钙瞬变的影响。方法9只雄性C57BL／6小鼠，随机分为3组：空白组、NRG‐1组、异丙肾上腺素组（即ISO组）。分别取其心脏，经主动脉逆行插管后行Langendorff灌流，以常规酶解法分离获得单个心室肌细胞，负载Fluo‐4钙荧光染料后，分别先后给予各组细胞0.5、1 Hz的电场刺激，运用活细胞工作站，记录每组细胞荧光强度的变化。结果与空白组相比，N RG‐1组能显著升高钙瞬变幅值ΔF／F0（ n＝10，P＜0.05），能缩短钙恢复时间RT50（从刺激开始至恢复到基线50％的时间）（n＝10，P＜0.05）；与 ISO组相比， N RG‐1组钙瞬变幅值、钙恢复时间、达峰时间均无显著差异（n＝10，P＞0.05）。结论 N RG‐1能升高正常心肌细胞钙瞬变幅度，缩短钙瞬变时程。