Cardioprotective effect of IGF-1 against myocardial ischemia/reperfusion injury through activation of PI3K/Akt pathway in rats in vivo

Figures

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  Figure 1.. Insulin-like growth factor-1 (IGF-1) attenuates myocardial ischemia/reperfusion (I/R) injury through activation of the PI3K/Akt pathway. (a) Representative photographs of triphenyltetrazolium chloride (TTC) and Evans blue-stained slices of rat heart. Blue color indicates nonischemic area, the area at risk (AAR) contains no blue dye, white color indicates infarct area (Inf), and red color indicates uninfarcted area. (b) Myocardial infarct size expressed as percentage of infarct area (Inf) over the AAR. (c) Serum lactate dehydrogenase (LDH) level. (d) Serum creatine kinase MB (CK-MB) level. (e) Serum cardiac troponin I (cTnI) level. Data are presented as means ± standard deviations (n = 4). *P < 0.05 vs. Sham group; **P < 0.05 vs. I/R group; &P < 0.05 vs. L-IGF-1 + I/R group; #P < 0.05 vs. H-IGF-1 + I/R group; NS, not significant.

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  Figure 2.. Insulin-like growth factor-1 (IGF-1) reduces myocardial cell apoptosis through activation of the PI3K/Akt pathway. (a) Representative images of immunofluorescent TUNEL staining (green color) and 4, 6-diamino-2-phenylindole staining (DAPI, blue color) taken with a fluorescence microscope (magnification, 400×). (b) Apoptotic index, expressed as the proportion of apoptotic myocytes relative to the total number of myocytes. Data are presented as means ± standard deviations (n = 4). **P < 0.05 vs. I/R group; &P < 0.05 vs. L-IGF-1 + I/R group; #P < 0.05 vs. H-IGF-1 + I/R group; NS, not significant.

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  Figure 3.. Insulin-like growth factor-1 (IGF-1) increases p-Akt (Ser473) protein expression and Bcl-2 protein and mRNA expression in rats with myocardial ischemia/reperfusion (I/R). (a) Representative western blots of p-Akt (Ser473) and Bcl-2 protein expression. (b) Quantification of p-Akt (Ser473) protein expression. (c) Quantification of Bcl-2 protein expression. (d) Quantification of relative Bcl-2 mRNA expression, as detected by qRT-PCR. Data are presented as means ± standard deviations (n = 4). *P < 0.05 vs. Sham group; **P < 0.05 vs. I/R group; &P < 0.05 vs. L-IGF-1 + I/R group; #P < 0.05 vs. H-IGF-1 + I/R group; NS, not significant.

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  Figure 4.. Insulin-like growth factor-1 (IGF-1) suppresses cleaved caspase-9 protein expression and caspase-9 mRNA expression in rats with myocardial ischemia/reperfusion (I/R). (a) Representative western blot and corresponding quantification of cleaved caspase-9 protein expression. (b) Quantification of relative caspase-9 mRNA expression, as detected by qRT-PCR. Data are presented as means ± standard deviations (n = 4). *P < 0.05 vs. Sham group; **P < 0.05 vs. I/R group; &P < 0.05 vs. L-IGF-1 + I/R group; #P < 0.05 vs. H-IGF-1 + I/R group; NS, not significant.