Myocardial protection from ischemia/reperfusion injury by exogenous galanin fragment

Figures

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  Figure 1. Dose-dependent effect of G1 on cell survival in response to oxidative stress Treatment of cardiomyoblasts with G1 prevents H2O2-induced decrease of cell viability in a dose-dependent manner. The H9C2 were pretreated with G1 (10, 50, 250 nM) for 20 min and then exposed to 400μM H2O2 for 4h. Values are the means ± SEM for three experiments. ***P < 0.001, vs control; §§P < 0.01, vs H2O2 treatment.

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  Figure 2. Effect of G1 on hypoxia-induced cell apoptosis A. Representative fluorescence images of H9C2 cells pretreated with 50 nM G1 for 20 min and then exposed to normoxia or hypoxia (1% O2) followed by reoxygenation. Apoptosis was measured by TUNEL assay in H9C2 cells after 16h of hypoxia followed by 4h of reoxygenation. B. Quantitative analysis of TUNEL-positive cells in H9C2 cells. Values are the means ± SEM from three experiments. ***P < 0.001, vs normoxia; §§§P < 0.001, vs hypoxia.

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  Figure 3. Effect of G1 on hypoxia-induced mitochondrial O2- production A. Representative fluorescence images of H9C2 cells pretreated with G1 peptide. Mitochondrial O2− formation was assessed by MitoSOX Red in H9C2 cells exposed to 16h hypoxia followed by 4h of reoxygenation. B. Quantitative analysis of mitochondrial O2− production in H9C2 cells exposed to normoxia or hypoxia-reoxygenation. Values are the means ± SEM from three experiments. ***P < 0.001 vs normoxia; §§§P < 0.001 vs hypoxia.

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  Figure 4. Dose-dependent effect of G1 infusion on functional recovery of isolated rat heart at the end of reperfusion A. Study design including three groups: 1 - Control; 2 - G1 infusion before ischemia; 3 - G1 infusion after ischemia; L - a 5-min Langendorff perfusion at a flow rate of 4 ml/min before or after ischemia; N, a working perfusion according to a method of Neely. B. Effects of peptide G1 on cardiac output (CO) recovery at the end of reperfusion. C. Effects of peptide G1 on the contractile function intensity index (left ventricular developed pressure (LVDP) × heart rate (HR)) recovery at the end of reperfusion. The values are expressed as means ± SEM from 8 experiments.

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  Figure 5. Effects of G1 infusion on metabolic state of isolated rat heart at the end of reperfusion St. - steady state; Contr. - control; G1-I - peptide infusion at the dose of 240 μM before ischemia; G1-R - peptide infusion at the dose of 240 μM after ischemia. A. Pre- or postischemic infusion of G1 improved recovery of myocardial ATP and adenine nucleotide pool (ΣAN) = (ATP+ADP+AMP) and B. adenylate energy charge (AEC) = (ATP+0.5ADP)/ΣAN) at the end of reperfusion. C. Infusion of G1 increased recovery of myocardial phosphocreatine (PCr), total creatine (ΣCr) = (PCr+Cr) and D. reduced myocardial lactate accumulation. Values are the means ± SEM from 8 experiments.*P < 0.05 vs. steady state; #P < 0.05 vs control, +P < 0.05 vs G1-I.

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  Figure 6. Effects of G1 on myocardial infarct size and area at risk in rats in vivo Dose-dependent effects of peptide G1 on A. area at risk (AAR) and B. myocardial infarct size. AAR was expressed as percentage of the left ventricular weight (AAR/LV, %) and myocardial infarct size (MI) was expressed as percentage of the AAR (MI/AAR, %). Control - i.v. bolus injection of 0.5 ml of saline; DMSO - i.v. bolus injection of 0.5% DMSO in saline; G1- i.v. bolus injection of peptide G1 at dose of 0.4, 0.7 or 1.3 μmol/kg. Values are the means ± SEM from 8 experiments.*P < 0.05 vs control.

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  Figure 7. Effects of G1 on plasma level of necrosis markers in rats in vivo Dose-dependent effects of peptide G1 on A. activity of creatine kinase-MB (CK-MB) and B. lactate dehydrogenase (LDH) in blood plasma. St. state - steady state; Control - i.v. bolus injection of 0.5 ml of saline; DMSO - i.v. bolus injection of 0.5% DMSO in saline; G1- i.v. bolus injection of peptide G1 at dose of 0.4, 0.7 or 1.3 μmol/kg. Values are the means ± SEM from 8 experiments.*P < 0.05 vs Control; ###P < 0.001 vs St. state.