Alprenolol and bromoacetylalprenololmenthane are competitive slowly reversible antagonists at the beta 1-adrenoceptors of rat left atria

  • J Cardiovasc Pharmacol. 1993 Jan;21(1):35-9. doi: 10.1097/00005344-199301000-00006.
A J Surman  1 ,  S A Doggrell
Affiliations
  • 1. Department of Pharmacology, School of Medicine, University of Auckland, New Zealand.
PMID: 7678677 DOI: 10.1097/00005344-199301000-00006
Abstract

We studied the effects of alprenolol and bromoacetylalprenololmenthane (BAAM) on rat left atria. Alprenolol and BAAM at 10(-7), 3 x 10(-7), and 10(-6) M inhibited the cardiac stimulation response slightly, which is indicative of membrane-stabilizing activity independent of beta-adrenoceptor blockade. This membrane-stabilizing activity was readily reversible. Alprenolol and BAAM also caused surmountable antagonism of isoprenaline responses, and this beta 1-adrenoceptor antagonism was slowly reversible. Inhibition of the isoprenaline responses with alprenolol and BAAM at 10(-6) M was at equilibrium after 60 min, which is indicative of reversible antagonism. We conclude that alprenolol and BAAM are competitive slowly reversible beta 1-adrenoceptor antagonists on rat left atria.

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