Effect of Phentolamine on Myocardial Extracellular Matrix of Cardiac Remodeling in Rats

Aim To study the effects of phentolamine on myocardial extracellular matrix of cardiac remodeling induced by norepinephrine in rats. Methods Twenty-four male SD rats were randomly divided into control group, norepinephrine group( model group) and norepinephrine + phentolamine group( treatment group). Left ventricular structure and function among groups of rats were measured by echocardiography. Extracellular matrix remodeling was evaluated by morphological examination,stained with Van-Gieson( VG). The content of hydroxyproline in the tissue of myocardium was measured. The protein expression of matrix metalloproteinase-2( MMP-2) and collagen Ⅰ were examined by immunohistochemical analysis. Results Compared with control group,left ventricular hypertrophy,the hydroxyproline content,collagen volume fraction( CVF) and protein expression of MMP-2 and collagen Ⅰ was significantly higher in the model group rats( P 0. 01). In treatment group rats,myocardial hypertrophy obviously improved,hydroxyproline,CVF reduced,protein expression of MMP-2 and collagenⅠdecreased( P 0. 05). Conclusion Phentolamine can prevent the cardiac hypertrophy and extracellular matrix remodeling,which was associated with the attenuation of myocardial MMP-2and collagen Ⅰ.