Plos One
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In order to determine the role of the adrenergic system in bupivacaine-induced cardiotoxicity, a series of experiments were performed. In an animal experiment, male Sprague-Dawley (SD) rats under chloral hydrate anesthesia received intravenous bupivacaine, followed by an intravenous injection of adrenalin or isoprenalin, and the electrocardiogram (ECG), left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), the maximum rate of rise of left ventricular pressure (+dP/dtmax) and the maximum rate of pressure decrease (-dP/dtmax) were continually monitored. In a cellular experiment, freshly isolated adult SD rat ventricular myocytes were perfused with bupivacaine at different concentrations in the presence or absence of isoprenalin, with or without esmolol. ⋯ Fifth, bupivacaine significantly increased the ROS in freshly isolated cardiomyocytes, and added isoprenalin induced a further enhancement of ROS production (P < 0.05, vs. bupivacaine alone). Added esmolol significantly decreased ROS production (P < 0.05, vs. bupivacaine + isoprenalin). Our results suggest that bupivacaine depressed cardiac automaticity, conductivity and contractility, but the predominant effect was contractile dysfunction which resulted from the disruption of mitochondrial energy metabolism. β-adrenergic activation aggravated the cellular metabolism disorder and therefore contractile dysfunction.