Effects and mechanism of different adrenergic receptor antagonists on left ventricular hypertrophy subsequent to coarctation of abdominal aorta in rats

摘要

Objective: To study the changes of a collagen-binding protein (Colligin) and myosin heavy chain isofrom (α/β-MHC) gene and protein in left ventricular hypertrophy subsequent to coarctation of abdominal aorta in rats and the effects of three kinds of adrenergic receptor blockers: Carvedilol (CAR), Metoprolol (MET) and Terazosin (TER) on these changes, and to elucidate the effects and new mechanism of CAR on left ventricular hypertrophy regression. Methods: A model of hypertrophy induced by coarctation of abdominal aorta(CAA) was used in this study. Thirty two male wislar rats were divided randomly into four groups 4 weeks after CAA operation: CAA, CAR, MET and TER. Hemodynamics, ventricular remodeling parameters, expressions of Colligin and α/β-MHC mRNA, protein expressions of Collagen Ⅰ/Ⅲ and Colligin were investigated in the four groups and sham operation group. Results: Left ventricle hypertrophy was observed clearly 16 weeks after operation. The ratio of α/β-MHC mRNA decreased, while expressions of CollagenⅠ /Ⅲ proteins and Colligin mRNA/protein increased( P < 0.05) . CAR could ameliorate left ventricle hypertrophy prior to MET and TER. CAR could also change the expressions of α/β-MHC, CollagenⅠ / Ⅲ and Colligin in both gene and protein levels ( P < 0. 05). while MET and TER have no effect on them ( P > 0.05) . Conclusion: The effects of CAR on extracellular matrix proteins and MHC isoform shift regression of left ventricle may be due to antiproliferative or antioxidative mechanism, which was independent of beta-adrenergic receptor antagonist.