| Objective Observe the protection of different concentration of emulsified isoflurane (EI) which continued on isolated myocardia against ischemia-reperfusion in rats and determine the optimum concentration of the protective effect.Methods Sixty-four male SD rats were devided into eight groups (n=8), Control group (C Group), ischemia-reperfusion group (IR Group), 0.28mmol/L EI Group (E1 Group), 0.56 mmol/L EI Group (E2 Group), 1.12mmol/L EI Group (E3 Group), 1.68mmol/L EI Group (E4 Group), 2.24mmol/L EI Group (E5 Group), 2.80mmol/L EI Group (E6 Group). Build the Langendorff model, after reaching balance in 20 min. K-H buffer perfusion is continued in Group C for 115 min; K-H buffer is continued in Group IR for 10 min, then 45 min ischemia followed by 60 min reperfusion with K-H buffer. K-H buffer is continued in different EI Group for 10 min, then 45 min ischemia followed by 60 min reperfusion with K-H buffer containing the corresponding concentration of EI. Write down the digital quantity of HR, LVDP, LVEDP,﹢dp/dtmax at the end of the balance, before ischemia, 20 min after reperfusion, 40 min after reperfusion and 60 min after reperfusion, measure the activity of LDH and SOD CTnI concentration at T0,2~4,; measure the area of myocardial infarction at the end of 60 min reperfusion.Result Difference of index values among groups at the end of balance and before ischemia were of no statistic significance (P> 0.05). Compared with the C Group, IR Group's HR, LVDP,﹢dp/dtmax , the activity of SOD all decreased, LVEDP, the activity of LDH and CTnI concentration increased (P<0.05); each EI Group's HR, LVDP decreased, LVEDP and the activity of LDH increased, the area of myocardial infarction also increased(P<0.05);the﹢dp/dtmax of E1 and E6 Groups increased, the activity of SOD all increased in E1~E5 Groups, the CTnI concentration all increased in E1~E3, E5, E6 Groups(P<0.05), the other of EI Groups'﹢dp/dtmax , the activity of SOD and CTnI concentration were no significant difference. Compared with IR Group, each EI Group's HR, LVDP,﹢dp/dtmax and the activity of SOD all increased, LVEDP, the activity of LDH and CTnI concentration decreased, the area of myocardial infarction also decreased(P<0.05). Compared with the E4 Group, the activity of LDH , CTnI concentration all increased(P<0.05)and the activity of SOD decreased(P<0.05)in each EI Group.Conclusion Emulsified isoflurane reduces the injury from ischemia-reperfusion of isolated myocardium of rats, thus playing a role in myocardial protection, with a proper concentration of 1.68mmol/L.Part II PI3K-Akt-GSK3βsignaling pathway involved in emulsified isoflurane on the isolated myocardia against ischemia-reperfusion in ratsObjective Discussion the protection of emulsified isoflurane which on isolated myocardia against ischemia-reperfusion in rats and the relationship of PI3K-Akt-GSK3βsignaling pathway.Methods The 32 male SD rats were devided into four Groups (n=8), which consist of the control Group (C Group), ischemia-reperfusion Group (IR Group), 1.68mmol/L EI Group (EI Group), 1.68mmol/L EI+100nmol/L Wortmannin Group (EW Group). Build the Langendorff model, measure the activity of LDH and CK, CTnI concentration in CF at the end of the balance, 20 min after reperfusion, 40 min after reperfusion and 60 min after reperfusion; measure.the area of myocardial infarction, the activity of Caspase-3 and Caspase-9 as well as the Akt and GSK3βphosphorylation level of myocardial cells at the end of 60 min reperfusion.Result Difference of index values among groups at the end of balance and before ischemia were of no statistic significance (P> 0.05). At the time of 20 min reperfusion, 40 min reperfusion, 60 min reperfusion,compared with the C Group,the activity of LDH and CK,CTnI concentration; the activity of Caspase-3 and Caspase-9 as well as the Akt and GSK3βphosphorylation level and the area of myocardial infarction all increased besides the C Group(P<0.05);compared with the IR Group, the activity of LDH and CK, CTnI concentration all decreased in EW and EI Groups, EI Group's activity of Caspase-3 and Caspase-9 decreased, the Akt and GSK3βphosphorylation level increased, EW Group's activity of Caspase-3 and Caspase-9 increased; the Akt and GSK3βphosphorylation level increased; the area of myocardial infarction all decreased(P<0.05);compared with the EI Group, EW Group's the activity of LDH and CK as well as CTnI concentration all increased; the Akt and GSK3βphosphorylation level all decreased, the activity of Caspase-3 and Caspase-9 and the area of myocardial infarction all increased(P<0.05).Conclusion Emulsified isoflurane can reduce the myocardial ischemia-reperfusion injury in rats; PI3K-Akt-GSK3βsignaling pathway was involved in the protective effect on myocardial ischemia-reperfusion injury of rats from emulsified isoflurane. |
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