Department of Anesthesiology, The Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, China.
Department of Anaesthesiology, North Jiangsu People's Hospital, Yangzhou University, Yangzhou, China.
BMC Anesthesiol. 2019 Jan 8;19(1):5. doi: 10.1186/s12871-018-0656-8.
Reperfusion ventricular arrhythmia (RA) associated with hypothermic ischaemic storage is increasingly recognized as a substantial contributor to adverse consequences after heart transplantation. Ischemia- or hypothermia-induced gap junction (GJ) remodelling is closely linked to RA. Reducing GJ remodelling contributes to RA attenuation and is important in heart transplantation. However, sevoflurane has an antiarrhythmic effect associated with the connexin 43 (Cx43) protein that has not yet been fully established.
Hearts were divided into two groups according to a random number table: all hearts were arrested by an infusion of histidine-tryptophan-ketoglutarate (HTK) solution (4 °C) followed by (1) storage in HTK solution (4 °C) alone for 6 h (n = 8, Control group) or (2) storage in HTK solution supplemented with sevoflurane (2.5%) (4 °C) for 6 h (n = 8, Sevo-HTK group). First, the total Cx43 level and the phosphorylation of Cx43 at Ser368 (Cx43-pS368) were assessed by Western blotting, and the distribution of Cx43 was assessed by immunohistochemistry. Second, programmed electrical stimulation (PES) and monophasic action potential (MAP) recording were used to analyse the MAP duration (MAPD), conduction velocity (CV) and transmural repolarization dispersion (TDR). In addition, haematoxylin and eosin (HE) and terminal deoxynucleotidyl transferase-dUTP nick end labelling (TUNEL) staining were individually used to investigate the degree of myocardial pathological damage and cell apoptosis. Finally, bipolar electrograms were used to record the graft re-beating time and monitor RA during reperfusion for 15 to 30 min.
Sevo-HTK solution relatively increased the total Cx43 (P < 0.01) and Cx43-pS368 (P < 0.01) levels and prevented Cx43 redistribution (P < 0.05) and CV slowing (P < 0.001) but did not change TDR (P > 0.05). Additionally, the Cx43-pS368/total Cx43 ratio (P>0.05) was similar in the two groups. However, with Sevo-HTK solution, the graft re-beating times were shortened, myocardial pathological damage was ameliorated, and the number of apoptotic cells was markedly decreased.
The reduction in hypothermia and ischaemia-induced reperfusion arrhythmias by the addition of sevoflurane to HTK solution may be related to the phosphorylation of Cx43 at serine 368.
低温缺血储存引起的再灌注性室性心律失常（RA）越来越被认为是心脏移植后不良后果的重要原因。缺血或低温诱导的缝隙连接（GJ）重塑与 RA 密切相关。减少 GJ 重塑有助于 RA 衰减，在心脏移植中很重要。然而，七氟醚具有与连接蛋白 43（Cx43）蛋白相关的抗心律失常作用，但尚未得到充分证实。
根据随机数字表将心脏分为两组：所有心脏均通过组氨酸-色氨酸-酮戊二酸（HTK）溶液（4°C）输注进行停搏，然后（1）仅在 HTK 溶液（4°C）中储存 6 小时（n=8，对照组）或（2）在 HTK 溶液中储存 6 小时，添加七氟醚（2.5%）（n=8，Sevo-HTK 组）。首先，通过 Western 印迹评估总 Cx43 水平和 Cx43 在丝氨酸 368 处的磷酸化（Cx43-pS368），并用免疫组织化学评估 Cx43 的分布。其次，使用程控电刺激（PES）和单相动作电位（MAP）记录分析 MAP 持续时间（MAPD）、传导速度（CV）和跨壁复极化离散度（TDR）。此外，苏木精和伊红（HE）和末端脱氧核苷酸转移酶 - dUTP 缺口末端标记（TUNEL）染色分别用于研究心肌病理损伤和细胞凋亡的程度。最后，双极电图用于记录移植物复跳时间，并在再灌注后 15 至 30 分钟监测 RA。
Sevo-HTK 溶液相对增加了总 Cx43（P<0.01）和 Cx43-pS368（P<0.01）水平，并防止 Cx43 重新分布（P<0.05）和 CV 减慢（P<0.001），但不改变 TDR（P>0.05）。此外，两组的 Cx43-pS368/总 Cx43 比值（P>0.05）相似。然而，使用 Sevo-HTK 溶液后，复跳时间缩短，心肌病理损伤改善，凋亡细胞数量明显减少。
在 HTK 溶液中添加七氟醚可减少低温和缺血再灌注引起的心律失常，这可能与 Cx43 在丝氨酸 368 处的磷酸化有关。
