Liver ischemia preconditions the heart against ischemia-reperfusion arrhythmias

Objective(s):This study aimed to examine the hypothesis that an antiarrhythmic effect might be obtained by ischemic preconditioning of the liver, and also to characterize the potential underlying mechanisms. Materials and Methods: Male Wistar rats were anesthetized by thiopental sodium (۵۰ mg/kg, IP) followed by IV injection of heparin (۲۵۰ IU). Remote ischemic preconditioning (RIPC) was induced by ۳ cycles of ۵ min liver ischemia followed by ۵ min of reperfusion. The hearts were excised within ۵ min after the final cycle of preconditioning and perfused using Langendorff’s system.            The isolated perfused hearts were subjected to ۳۰ min global ischemia followed by ۹۰ min reperfusion. The myocardial arrhythmias induced by ischemia- reperfusion (I/R) were determined in accordance with the guidelines of Lambeth Conventions. The potential role of KATP channels on RIPC was assessed by injection of glibenclamide (nonselective KATP blocker) or             ۵-hydroxydecanoate (mitochondrial KATP blocker) on rats ۳۰ and ۱۵ min before induction of RIPC in the liver, respectively. Results: Hepatic remote preconditioning of the heart significantly (P<۰.۰۰۰۱) prevented the incidence of myocardial arrhythmias induced by I/R in the perfused hearts (۵.۳۳±۱.۵۴ vs. ۳۲.۳۳±۶.۴۴,). However, the protective effects of remote preconditioning was significantly (P<۰.۰۱) abolished by the KATP blocker, glibenclamide (۲۵.۵±۴.۹ vs. ۵.۳۳±۱.۵۴,). Conclusion: Hepatic RIPC may prevent the arrhythmias induced by I/R in the isolated perfused hearts via KATP channels.

Keywords:

Ischemia-reperfusion arrhythmia , Isolated heart , Liver , Remote ischemic , Preconditioning