Tea polyphenols promote cardiac function and energy metabolism in ex vivo rat heart with ischemic/reperfusion injury and inhibit calcium inward current in cultured rat cardiac myocytes
DONG Huajin
LI Jie
ZHAN Hao
LI Yang
SU Ruibin
Abstract：Objective To investigate the protective effects of tea polyphenols (TP) against myocardial ischemia/reperfusion (IR) injuries and explore the possible mechanisms. Methods Langendorff-perfused rat hearts were subjected to ischemia for 30 min followed by reperfusion for another 30 min. Myocardial function indices were measured by a left ventricular cannula via a pressure transducer connected to the polygraph in isolated Langendorff hearts and energy metabolism was measured using 31P nuclear magnetic resonance (NMR) spectroscopy. Whole-cell patch-clamp technique was used to record calcium inward current (ICa- L) in cultured rat cardiac myocytes. Results Compared with the control hearts, the ex vivo rat hearts with 2.5 mg/L TP treatment showed significantly increased left ventricular developed pressure (LVDP), maximal rise rate of LVDP (+dp/dtmax), maximal fall rate of LVDP (-dp/dtmax), and coronary flow (CF) (P<0.05). During both cardiac ischemia and reperfusion phase, ATP and PCr levels were elevated significantly in TP-treated hearts compared with those in the control hearts (P<0.05). In cultured rat cardiac myocytes, ICa-L was remarkably decreased by TP at the doses of 2.5 and 5.0 mg/L (P<0.01). Conclusion Our results support a possible protective role of TP against myocardial IR injury by improving myocardial energy metabolism and inhibiting ICa-L in the cardiac myocytes.
Keywords：tea polyphenolscardiac functionischemia/reperfusionenergy metabolismcalcium inward current
Publication Date：2016-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 604-608 )