Cardioprotective and Anti-arrhythmic Effects of Magnesium Pretreatment Against Ischaemia/Reperfusion Injury in Isoprenaline-Induced Hypertrophic Rat Heart
Cardioprotective and Anti-arrhythmic Effects of Magnesium Pretreatment Against Ischaemia/Reperfusion Injury in Isoprenaline-Induced Hypertrophic Rat Heart
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DOI：
10.1007/s12012-015-9355-6
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发表时间：
2017-01-01
影响因子：
3.2
通讯作者：
Gwanyanya, Asfree
中科院分区：
文献类型：
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作者：
Amoni, Matthew;Kelly-Laubscher, Roisin;Gwanyanya, Asfree
镁离子对病理性心肌肥厚的缺血性并发症的影响尚不清楚。在本研究中，我们观察了镁离子预处理对异丙肾上腺素(ISO)诱导的肥厚心脏缺血/再灌注(I/R)损伤的影响。给Wistar大鼠皮下注射ISO(1.25 mg/kg)、腹腔注射硫酸镁(270 mg/kg)或生理盐水，连续7d。在第8天，心脏接受朗宁多夫灌流期间的局部I/R，或苏木精-伊红-马森氏三色染色。用PowerLab数据采集系统记录血流动力学和心电图参数。用氯化三苯基四氮唑染色鉴定心肌梗死。采用分光光度法测定血浆镁离子浓度。在肥厚的心脏中，镁离子预处理显著减少了I/R诱发的室性早搏、室性心动过速和室颤的I/R诱发的梗塞范围(p=0.001)和总的心律失常评分(p<；0.001)，但对非肥厚的心脏没有影响。镁离子还可改善肥厚心脏I/R后左室发展压。然而，镁离子不能逆转ISO诱导的心肌细胞增厚和间质纤维化或心脏重量增加。各治疗组间血浆镁离子水平无明显差异。这些结果提示，镁离子预处理对肥厚心脏I/R损伤和恶性心律失常有保护作用，其机制可能与血浆镁离子的长期变化或防止纤维化等结构改变无关。
The effects of magnesium (Mg2+) on ischaemic complications of pathological cardiac hypertrophy are unclear. In this study, we investigated effects of Mg2+ pretreatment on ischaemia/reperfusion (I/R) injury in isoprenaline (ISO)-induced hypertrophic hearts. Wistar rats were treated for 7 days with different combinations of ISO (1.25 mg/kg) subcutaneously, MgSO4 (270 mg/kg) intraperitoneally, or vehicle (saline). On the eighth day, hearts were either subjected to regional I/R during Langendorff perfusion or histologically stained with haematoxylin and eosin and Masson's trichrome. Haemodynamic and electrocardiographic parameters were recorded using the PowerLab data-acquisition system. Infarcts were identified by triphenyltetrazolium chloride staining. Plasma Mg2+ was measured using photometric assays. Mg2+ pretreatment significantly decreased I/R-induced infarct size (p = 0.001) and the overall arrhythmia score (p < 0.001) of I/R-induced ventricular ectopics, ventricular tachycardia, and ventricular fibrillation in hypertrophic hearts, but not non-hypertrophied hearts. Mg2+ also improved post-I/R left ventricular developed pressure in hypertrophic hearts. However, Mg2+ did not reverse the ISO-induced myocyte thickening and interstitial fibrosis or increases in heart weight. Plasma Mg2+ was not different among treatment groups. These results suggest that Mg2+ pretreatment may protect against I/R-induced injury and malignant arrhythmias in hypertrophic hearts, possibly via mechanisms unrelated to long-lasting changes in plasma Mg2+ or prevention of structural changes such as fibrosis.