Study On The Effect And Mechanism Of Potenline On Myocardial Ischemia By Traditional Chinese Medicine Injection

There is a clear trend towards an increased incidence of cardiovascular disease.Myocardial ischemic injury（MII）is a common cause of cardiovascular disease.Oxidative stress and calcium overload are common causes of myocardial ischemic injury.Oxidative stress refers to the process of oxidative damage caused by increased production or reduced scavenging of oxygen free radicals in tissues or cells,resulting in the accumulation of reactive oxygen species（ROS）in the body or in cells.Excess free radicals that undergo oxidative reactions trigger tissues and cells damage.The interaction between free radicals and membrane unsaturated fatty acids leads to lipid peroxidation,which makes the ratio of membrane unsaturated fatty acids and protein out of balance.Therefore,the fluidity and permeability of cell membrane and organelle membrane are decreased,the calcium ion influx is increased,and the function of membrane protein is indirectly inhibited.This leads to the increase of calcium concentration in the cytoplasm,cell swelling and calcium overload.Furthermore,it causes damage to the mitochondrion of cardiomyocytes,myocardial necrosis and arrhythmia,and subsequent deterioration of cardiac function.Exogenous Ca²⁺enters cells mainly through L-type calcium channels,and L-type calcium channel blockers can protect against myocardial ischemia injury by inhibiting calcium channels.Potenline,a traditional Chinese medicine injection,has been widely used in the clinical treatment to improve liver function,promote bilirubin metabolism,inhibit viral hepatitis,and as an adjunct to tumor radiotherapy and chemotherapy,but studies on its anti-myocardial ischemic effect and its mechanism have not been reported.In this study,we explored the protective effect and mechanism of Potenline on myocardial ischemia injury from animal and cell experiments.Part 1 Study on the protective effect of Potenline,a Chinese medicine injection,on rats with myocardial ischemia induced by isoproterenolObjective:To investigate the protective effect of Potenline on rats with myocardial ischemia induced by isoproterenol（ISO）by biotechnology.Methods:40 adult male SD rats were randomly divided into 4 groups:blank control group（Con group）,isoproterenol model group（ISO group）,Potenline treatment group（Potenline group）and verapamil group（Ver group）,with 10 rats in each group.Con group and ISO group were respectively injected intraperitoneally with normal saline.Potenline group was injected intraperitoneally with Potenline（30 mg/kg/d）and Ver group was injected intraperitoneally with verapamil（2 mg/kg/d）.After 1 week of continuous treatment using the above methods,the Con group was injected subcutaneously with saline and the remaining groups were injected subcutaneously with ISO（85 mg/kg/d）for 2 consecutive days.Results:1.Potenline significantly reduced the heart rate and J-point elevation of MII rats;2.Potenline significantly reduced the left ventricular end-diastolic pressure in MII rats,and significantly increased the left ventricular systolic pressure,the maximum rate of increase in ventricular indoor pressure and the maximum rate of decrease in left ventricular indoor pressure in MII rats;3.Potenline significantly reduced the activity of creatine kinase（CK）and lactate dehydrogenase（LDH）in serum of MII rats;4.Potenline significantly increased the activity of superoxide dismutase（SOD）and glutathione（GSH）in myocardial tissues from MII rats,and significantly decreased the concentration of malondialdehyde（MDA）and free calcium ions in myocardial tissues;5.Potenline significantly improved the pathological symptoms of cardiomyocyte swelling,degeneration and loss of transverse striations in MII rats,and significantly improved the pathological symptoms of myocardial mitochondrial swelling,twisting,narrowing and partial disappearance of Z-line,myofibrillar lysis;6.Potenline significantly reduced the level of reactive oxygen species（ROS）in heart tissues of MII rats.Part 2 Effect of Potenline,a Chinese medicine injection,on L-type calcium channels of cardiomyocytes of ratsObjective:To investigate the mechanism of myocardial protective by observing the Potenline regulation of LTCCs of cardiomyocytes of rats.Methods:Whole-cell patch-clamp technique was used to observe the effect of Potenline on LTCCs of cardiomyocytes of rats.Results:1.Potenline inhibited L-type calcium currents(I_Ca-L)in a concentration-dependent way,with concentrations of Potenline of 10^-6,3×10^-5,10^-5,3×10^-4 and 10^-4 M,and with the corresponding inhibition rates of 11.46±0.80%,18.76±0.81%,29.19±2.10%,45.33±0.63%and 54.32±2.53%,respectively;2.Potenline with a concentration of 10^-4 M significantly inhibited I_Ca-L in normal and ischemic cardiomyocytes,with inhibition rates of 54.32±2.53%and 55.67±2.37%,respectively;3.Potenline with a concentration of 10^-6,10^-5 and 10^-4 M significantly moved up the I-V relation curve while the activation potential and peak potential remain unchanged;4.Potenline had no significant effect on steady-state activation and deactivation of I_Ca-L.Conclusion:Potenline has a cardiopretection effect on ISO-induced MII rats,and the mechanism is related to its ability to inhibit oxidative stress,inhibit LTCCs to reduce calcium ion internal currents,and reduce calcium ion concentration.