The Effects And Mechanism Of Glycyrrhizin On Rat Myocardium Injury Induced By R5 Type HIV-1gp120

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Preparation and Evaluation Rat Experimental Model of Myocardium Injury Induced by R5 type HIV-1 gp120OBJECTIVE: To prepare an experimental model of rat injured by R5 type HIV-1 gp120 and evaluate its myocardium damage.METHODS: 20 4-week-old male SD rats were randomly divided into two groups(n=10)that werenormal control group(CON)and HIV-1 gp120 model group(gp120).Rats in gp120 group were injected with R5 type HIV-1 gp120(50 ?g/Kg)from the tail vein and 10 ml/kg normal saline(NS)was intragastric administration once a day.In the CON group,NS(50 ul/kg)was injected into the tail vein of rats,and the others steps were same with gp120 group.Rats in two groups were both fed for 4 weeks,recorded body weight and fasted for 12 hours before the experiment.Then anesthesia with urethane,measuring arterial blood pressure,left ventricular intubation and measuring left ventricular pressure analysis of hemodynamic parameters(HR,LVSP,LVDP,LVP±dp/dtmax).And dose-effect on isoproterenol,blood of rats was collected from the abdominal aorta to measure blood lipids,and ultrastructure of cardiomyocytes were detected by transmission electron microscopy.RESULTS: Compared with the CON group,the gp120 group had more weight gain(p<0.05),higher arterial blood pressure(p<0.05)as well as decreased systolic and diastolic potential(p<0.05).In addition,the ultrastructure of myocardial cells,and myofibril,mitochondrial damage,collagen fibrosis,visible phagocytic lysosomes were found in this study.CONCLUSION: The rat model of HIV-1 gp120 injury can be prepared by tail-injection of R5 type HIV-1 gp120(50?g/Kg)under the exposure of 4 weeks.The manifestations are concentric obesity,elevated blood pressure,decreased systolic and diastolic potential,myocardial ultrastructural changes.Part ? The Protection Effects of Glycyrrhizin on of Rat Myocardium Injury Induced by R5 HIV-1 gp120OBJECTIVE: To explore the protective effect and mechanism of glycyrrhizin(GL)on myocardium injury of rat induced by R5 type HIV-1gp120.METHODS: Forty-eight male Sprague-Dawley rats aged 4 weeks were divided into 4 groups(n=12),which were CON group,gp120 group,50 mg/kg glycyrrhizin protection group(gp120+GL50)and 100 mg/kg glycyrrhizin protection group(gp120+GL 100)respectively.In the CON group,NS(50 ul/kg)was injected into the tail vein and intragastric administration was given once a day with NS(10 ml/kg).Rats of other three groups were injected with R5 type HIV-1 gp120(50 ?g/Kg).The difference is that gp120 group received NS 1 time / day(10 ml/kg),gp120 + GL 50 and gp120 + GL 100 groups were given 50 and 100 mg / kg glycyrrhizin by intragastric administration respectively once a day.Rat body weights were recorded for 42 days continuously.After the last time dose of rats in each group,fasting for 12 hours and abdominal anesthesia was performed.Thenleft ventricular pressure analysis hemodynamic parameters(HR,LVSP,LVDP,LVP ± dp / dtmax)were tested from left ventricular intubation of rats,determination of four lipids(TG,TC,LDL-C,HDL-C),aspartate aminotransferase(AST),alanine aminotransferase(ALT),lactate dehydrogenase(LDH),phosphokinase(CK).Determination of GSH,sodium +-K + ATPase,ALT,AST in myocardial tissue were tested from the abdominal aorta blood.Moreover,observation of myocardial histological structure by HE staining,and observing the fibrosis of myocardial tissue by Masson staining were performed.RESULTS: Compared with CON group,gp120 group had more weight gain,left ventricular maximum systolic velocity and diastolic velocity were faster(P<0.05);blood lipid LDL-C were lower(p<0.05)and HDL-C were higer(p<0.05).Meanwhile,Serum GSH were statistically reduce(p<0.05),myocardial enzyme CK,LDH increased(p<0.05);higer myocardial tissue ALT,AST and GSH were found(p<0.05);myocardial tissue HE staining observed myocardial fiber edema,disorder Inflammatory cell infiltration;Masson staining showed more collagen fibers in myocardial tissue compared with CON group.Compared with gp120 group,GL(100mg/Kg·d gavage)intervention rats had less weight gain(p<0.05).Left ventricular maximum systolic and diastolic velocity in resting heart state were faster(p<0.05);blood lipid LDL-C decreased and HDL-C increased(p<0.05);serum GSH increased(p<0.05),plasma myocardial enzyme CK leakage were less(p<0.05).The activity of myocardial tissue ALT and AST were strengthened(p<0.05),while activity of GSH and Na+-K+ATPase were weakened(p<0.05).Myocardial histological structure was close to normal;myocardial tissue fibrosis was less than gp120 group.Conclusion: The rat model of HIV-1 gp120 injury was induced by tail vein injection of R5 type HIV-1gp120(50?g/Kg)for 6 weeks.which showed obesity,impaired cardiac function,elevated blood lipids and serum resistance,reduced oxidative capacity.Glycyrrhizin(100mg/Kg·d)intervention can protect rats from R5 type HIV-1 gp120 injury,maintain weight gain and normal lipid metabolism and anti-oxidation metabolism,protect the myocardial function,metabolism as well as structure of rats.