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Objective To study the protective effects of propofol pretreatment on ischemia-reperfusion injury in rabbit heart. Methods Forty New Zealand white rabbits (40 male, weighting 2. 5 ± 0. 36kg) were randomly assigned to 4 groups, including sham operation group, ischemia reperfusion (IR)group, IR + ischemia preconditioning (IP) group and IR + Propofol preconditioning (PP) group (n =10 each). The myocardial ischemia-reperfusion model of rabbits was established by coronary artery ligation.The levels of high energy phosphates (ATP, ADP and AMP) in myocardial tissue were measured by HPLC.The activities of serum lactate dehydrogenase (LDH), serum creatine kinase-MB (CK-MB) superoxide dismutase (SOD) and malondiadehyd (MDA) in myocardial tissue were assayed. Results The content of ATP, ADP, AMP, and the activity of SOD in PP group and IP group were higher than that of IR group, and the content of LDH, MDA and CK-MB in injured myocardial tissue in PP group and IP group were obviously lower than that of IR group (P ＜0. 05, P ＜0. 01). No difference was found in PP group and IP group(P＞0. 05). Conclusion Propofol preconditioning as well as ischemia preconditioning protected the myocardial tissues from the ischemia-reperfusion injury by improving the myocardial energy metabolism, the debasement of the oxyradical level and the antagonism the reaction of lipid peroxides.
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Objective To study the feasibility and safety of limb remote ischemic preconditioning (RIPC) in infants and explore the protective effect on myecardium ischemia reperfusion injury for infants undergoing cardiac operation under cardiopulmonary bypass. Methods 60 infants weight less than 7 kilograms with ventricular septal defect were enrolled into the study. 30 of them (RIPC group) were ischemic preconditioned two times (24 hours and 1 hour preoperatively) by three cycles of iscbemia (5 minutes for each) and reperfusion on the left upper arm using a blood pressure cuff. Serum lactate dehydrogenase (LDH), creatine kinase (CK) and its isoenzyme (CK-MB), and tro-ponin I (TnI) ; malondialdehyde (MDA) and superoxide dismutase (SOD) was preoperatively detected. The expression of heat shock pro-tein 70 (HSP 70) in cardiomyocytes was determined by western blot analysis. The surgical outcome including limb movement and sensory function was also recorded. Results No limb disability or sensory disturbance or no other surgical complications was found in all infants. LDH, CK, TnI at the beginning of operation in RIPC group was higher than those in control group. After operation, leakage of heart enzymes were attenuated in RIPC group, and the serum concentration of enzymes were lower than those in the control group. The RIPC group had low coronary sinus venous concentration of MDA but high SOD. The expression of HSP70 was upregulated in cardiomyocytes of RIPC group. Conclusion The limb RIPC can be done easily and safety in infants, and BIPC can reduce the leakage of myocardial enzymes and upregu-late the expression of HSP, which possess protective effect on myocardial IRI.
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Objective To observe the protective effect of magnesium gluconate on myocardial apoptosis by ischemia reperfusion injury in isolated rat hearts, and study the possible mechanism. Methods The hearts of 48 Sprague-Dawely rats were isolated, linked to Lange-ndorff perfusion apparatus, and randomly divided into 3 equal groups(n = 16 each) : Control group, ischemia/reperfusion (I/R) group and magnesium gheonate group. 8 rats in each group were perfused. Control group was pedused with modified KH buffer for 110min. I/B group was perfuesd with modified KH buffer for 20 min, then exposed to iscbemia for 30 min, and then reperfused with modified KH buffer for 60 min. Magnesium gheonate group was perfumed with modified KH buffer with magnesium gluconate for 20 min, then exposed to isohemia for 30 min and then reperfused with modified KH buffer with magnesium glueonate for 60 min. Lacate dehydrogenase (LDH) and ereatine kinase (CK) in the effluent liquid from the heart were measured after reperfusion. The concentration of Ca2+ and NO in the left ventricle were determined. The other 8 rats in each group were reperfused for 120 minutes as the method described before. After repeffusion, the myoeyte apoptosis was examined by Annexin-V-FITC/PI. After the two experiments the incidence of ventrieular arrhytlunias during reperfusion was assessed. Results Compared with I/R, magnesium glueonate decreased the incidence of ventricular an'hythmias(P <0. 01). The contents of CK and LDH in the effluent liquid from the heart in magnesium glueonate group was lower than that of I/R group (P <0. 01). The contents of Ca2+ and NO in the left ventricle in magnesium gluconate group was decreased than that of I/R group (P <0. 01). The index of myocyte apoptosis were significanfly lower in magnesium glueonate group than that of I/R group (apoptosis index :27.79±1.59 vs 33.61±2.10, P < 0. 01) . Conclusion Magnesium glueonate has protective effect on myocardial isohemia reperfusion injury in rats. The protective effect may be related to decreasing myocyte apoptosis by increasing the content of NO and relieving calcium overload.
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lsartan could reduce the release of p-selectin.Conclusions Valsartan could relieve myocardial ischemia reperfusion injury of rat, which may be through reducing p-seleetin of plasma.