Functional antagonism of β-adrenoceptor subtypes in the catecholamine-induced automatism in rat myocardium.

ABSTRACT:

Background and purpose

Myocardial automatism and arrhythmias may ensue during strong sympathetic stimulation. We sought to investigate the relevant types of adrenoceptor, as well as the role of phosphodiesterase (PDE) activity, in the production of catecholaminergic automatism in atrial and ventricular rat myocardium.

Experimental approach

The effects of adrenoceptor agonists on the rate of spontaneous contractions (automatic response) and the amplitude of electrically evoked contractions (inotropic response) were determined in left atria and ventricular myocytes isolated from Wistar rats.

Key results

Catecholaminergic automatism was Ca(2+) -dependent, as it required a functional sarcoplasmic reticulum to be exhibited. Although both α- and β-adrenoceptor activation ca

SUBMITTER: Boer DC 

PROVIDER: S-EPMC3058164 | biostudies-literature | 2011 Mar

REPOSITORIES: biostudies-literature