Effect of phentolamine on myocardial extracellular matrix of cardiac remodeling in rats

Objective:To study the effects of phentolamine on myocardial extracellular matrix of cardiac remodeling induced by norepinephrine in rats.Methods:24 SD rats were divided into 3 groups randomly:control groups,norepinephrine groups(model groups),norepinephrine +phentolamine groups(treatment groups).Echocardiography was used to detect changes in cardiac structure and function,the level of collagen volume fraction(CVF) and hydroxy-proline as well as collagen content were determined in myocardial tissue,matrix metalloproteinases-2 and collagen Ⅰin myocardial tissue were localized by immunohistochemitry.Results:Compared with control groups,left ventricular hypertrophy in the model group rats,the livdioxyproline content and CVF was significantly higher(P<0.01),and matrix metalloproteinase- 2 and collagen Ⅰ protein expression was significantly increased(P<0.01).Phentolamine significantly improved cardiac hypertrophy in treatment group rats,reduced hydroxy-proline,CVF,matrix metalloproteinase 2and collagen Ⅰ protein expression(P<0.05).Conclusions:Phentolamine can effectively reduce the incidence of myocardial hypertrophy and myocardial extracellular matrix remodeling in SD rats,and it can ease myocardial extracellular matrix of cardiac remodeling.It may he associated with reduced expression of matrix metalloproteinase 2 and collagen Ⅰ in myocardial tissue remodeling.