| Objective To investigate the expression of C3G protein in the non-infarcted myocardium and its regulation by phenylephrine(PE) in rats.Methods Myocardial infarction (MI)and sham-operation were established by Litwin's method. Three days after operation, surviving Sprague-Dawley male rats were divided into MI group (n=8), sham group(n=8), MI+PE group(n=8), sham+PE group(n=8). MI and sham groups were treated with physiological buffered saline 1ml/kg intraperitoneally every day for 8 weeks respectively; MI+PE and sham+PE groups were treated with PE 0.65mg/kg intraperitoneally every day for 8 weeks respectively. Twelve weeks after treatment,the expression of C3G protein in non-infarcted myocardium were detected by immunohistochemistry and Western blot respectively.Results Twelve weeks after treatment, the numbers of C3G protein positive staining cells detected by immunohistochemistry in non-infarcted myocardium were (96.5±3.43) in MI group, (68.88±4.17) in sham group, (80.38±3.10) in MI+PE group and (69.5±3.68) in sham+PE group respectively. The integration optical density of C3G protein detected by Western blot in non-infarcted myocardium was (0.81±0.05) in MI group, (0.33±0.06) in sham group, (0.62±0.07) in MI+PE group and (0.40±0.06) in sham+PE group respectively. The expression of C3G protein in non-infarcted myocardium was significantly increased in MI group as compared with sham group( P <0.05); and in MI+PE group as compared with sham+PE group( P <0.05). The expression of C3G protein in non-infarcted myocardium was significantly decreased in MI+PE group as compared with MI group(P <0.05); However, there was no any difference in the expression of C3G protein in non-infarcted myocardium between sham+PE group and sham group(P>0.05).Conclusion The expression of C3G protein was significantly increased in the non-infarcted myocardium. However, PE can significantly down-regulate the expression of C3G protein in the non-infarcted myocardium. But, the role of C3G protein in the post-infarction left ventricular remodeling remains to be further clarified. |
