@article{APS7825,
author = {Yong-zhen ZHANG and You-yi ZHANG and Ming-zhe CHEN and Qi-de HAN},
title = {Beta-Adrenoceptors potentiate alpha1-adrenoceptor-mediated inotropic response in rat left atria},
journal = {Acta Pharmacologica Sinica},
volume = {25},
number = {1},
year = {2016},
keywords = {},
abstract = {AIM:
To investigate whether stimulation of beta-adrenoceptor (AR) and its subtypes augment alpha1-AR-evoked positive inotropic response and inositol phosphate (InsP) accumulation in isolated rat left atria.
METHODS:
Inotropic response was determined by contractile function experiment in isolated electrically driven rat left atria. 3H-InsP accumulations were measured by 3H-inositol incorporation and column chromatography.
RESULTS:
(1) Stimulation of alpha1-AR by phenylephrine (PE) or norepinephrine (NE) in the presence of propranolol (Prop) evoked positive inotropic response and 3H-InsP accumulations, while stimulation of beta-AR by isoprenaline (ISO) or NE in the presence of phentolamine (Phen) only evoked positive inotropic response, but not 3H-InsP accumulations. (2) Simultaneous stimulation of alpha1- and beta-AR by NE or ISO plus PE significantly shifted the concentration-dependent inotropic response curves and 3H-InsP accumulation curves to the left and upward compared with individual alpha1-AR stimulation by PE or NE in the presence of Prop. (3) In the presence of ICI118551 (selective beta2-AR antagonist) or CGP12177 (selective beta1-AR antagonist), stimulation of either beta1- or beta2-AR did not change alpha1-AR-evoked inotropic response and 3H-InsP accumulations.
CONCLUSION:
Stimulation of beta1-AR and beta2-AR potentiates alpha1-AR-mediated positive inotropic response and InsP accumulation in isolated rat left atria.},
issn = {1745-7254}, url = {http://www.chinaphar.com/article/view/7825}
}