Objectives: To investigate the expression of β3-adrenoceptors in rats with chronic heart failure, and to explore the effect of β-blockers on β3-adrenoceptor expression.Methods: Thirty-two male Wistar rats were divided into Sham (n=10) and heart failure (n=22) groups. The heart failure group was treated with normal saline (Heart Failure Control, n=6), Metoprolol (n=8) or Carvedilol (n=8) for three months.Results: The left ventricular end systolic pressure (LVESP) and the absolute values of maximal rate of rise and fall of left ventricular pressure (±dP/dt max) in the heart failure group were lower than in the Sham group (P<0.01), whereas the left ventricular end diastolic pressure (LVEDP) was higher (P<0.01). The LVESP and dP/dtmax in the Carvedilol group were higher than the Metoprolol group whereas LVEDP was lower (P<0.01). The left ventricular mass index (LVMI) in the Carvedilol group was less than the Metoprolol and Heart Failure Control groups (P<0.01). The level of β3-adrenoceptor expression in the study groups was significantly higher than the Sham group (P<0.01). β3-adrenoceptor expression in the Carvedilol group was lower than the Heart Failure Control and Metoprolol groups (P<0.01).Conclusion: β3-adrenoceptor expression is increased in the failing ventricles in rats. Carvedilol is more effective than Metoprolol for improving the hemodynamics and in attenuating ventricular remodeling after heart failure. Carvedilol, rather than Metoprolol, diminishes β3-adrenoceptor expression in the failing ventricles.
Zhao, Q., Wu, T., Jiang, Z-F., Chen, G-W., Lin, Y., & Wang, L. (2007). Effect of β-blockers on β3-adrenoceptor expression in chronic heart failure. Cardiovascular Drugs and Therapy, 21(2), 85-90. https://doi.org/10.1007/s10557-007-6016-4