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Updated: Jul 10, 2026

Isolation of Human Atrial Myocytes for Simultaneous Measurements of Ca2+ Transients and Membrane Currents
Published on: July 3, 2013
A beta-2-adrenergic receptor activates adenylate cyclase in human erythrocyte membranes at physiological calcium
J F Horga1, J Gisbert, J C De Agustín
1Department of Pharmacology and Therapeutics, University Miguel Hernández, San Juan, Alicante, Spain. jfhorga@umh.es
Abstract:
More information is needed about the subtype of the beta-adrenergic receptor coupled to the G-protein-adenylate cyclase (AC) system in human erythrocytes and about the optimal experimental conditions to study this system. In this study we describe the characteristics of spontaneous and beta-agonist-activated AC in human erythrocytes. Human erythrocyte membranes were isolated and AC activity was utilized to assess the quantity of cAMP. Our data show that the subtype beta-2 is the functional beta-adrenergic receptor involved in such activation; this modifies the beta-adrenergic-stimulated activity of AC in human erythrocytes. Isoproterenol in a medium with calcium (1-10 mM, range that includes physiological plasma concentrations) enhances the activation of AC; this effect was blocked by propranolol, but not by atenolol. We conclude that in human erythrocytes subtype beta-2 is the functional beta-adrenergic receptor and that such a response depends to a large extent on Ca(2+) concentrations.
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