Cardioprotective Effect On Myocardial Hypoxia Injury By Ethanol Extract Of Lycopus Lucidus Turcz Via Hypoxia-inducible Factor-1 In Rats

Objective1.Observe the cardioprotective effects by ELT on myocardial hypoxia injury in rat’s isolated perfused beating atrium;2.Reveal the influence on PI3K/Akt signaling system regulated HIF-1α.HO-1 protein’s expression while ELT confronting myocardial ischemic damage;3.Reveal ELT can improve the structure and morphology of myocardial cells on myocardial hypoxia injury in rat’s.MethodsHealthy grade SD rats were divided into five groups in random:control group,HY group,ELTH group,HY + ELTH group,HY + ELTL group.We made in rat’s isolated perfused beating atrium.Electrophysiology and radioactive immunology test:Use BL-420S polygraph to systematically analyze the change of myocardial contractility;Use radioactive immune test box and multi-tube radiation immunity arithmometer to measure the change of ANP secretion in atrium perfusion liquids.Use Western blotting method to detect the protein expression level of HIF-1α,HO-1 and p-Akt.Use immumohistochemical staining to measure the expression of HIF-1α and HO-1.Use HE staining method to observe the structural change of myocardial cells.Use transmission electron microscope to observe the ultrastructure of cardiac muscle tissue.Results1.The study indicated that ELT significantly improved the myocardial contractility(P<0.05)and attenuated ANP secretion that had been improved by myocardial hypoxia injury in isolated perfusion rat atrial model(P<0.05).2.ELT significantly increased HIF-la,HO-l and p-Akt protein expression levels(P<0.05)in myocardial hypoxia injury.3.Through adopting immunocytochemistry method we found that compraring to the HY group the signals of HIF-1α、HO-1 protein expression in HY+ELTH group are significantly enhanced(P<0.05).4.Through HE staining method we found ELT significantly improved the changes of myocardial cells’ structure alignment and intercellular space that caused by ischemic myocardial damage.5.The ultrastructure observation indicated that the damage of myocardial cells in HY+ELTH group was apparently relieved.ConclusionsELT had protective effects on myocardial hypoxia injury and its possible mechanism may be related to the regulating of HIF-1α by PI3K/Akt signaling pathway with increasing of HO-1 protein levels.