Unsuitability of the Human Erythrocyte as a Model for in Vivo Sodium Transport Activation by Beta 2 Adrenergic Agonists

Abstract

Administration of the beta₂ adrenergic agonists fenoterol, salbutamol and terbutaline to volunteers significantly reduced plasma potassium concentration in a double-blind crossover study. There was no consistent effect of the three active compounds on erythrocyte sodium concentration. Storage of whole blood at 4°C increased erythrocyte sodium concentration by 33% after 2 h; this could explain the differences between this and another study of the effects of beta₂ adrenergic agonists on erythrocyte sodium concentration. We conclude that the human erythrocyte is unsuitable as an indirect in vivo model to demonstrate stimulation of cellular sodium potassium transport mediated by beta₂ adrenergic agonists.