The effect of catecholamines and prostaglandins upon human and rat erythrocytes

Abstract

Both human and rat erythrocytes respond to low doses (10 −11-10 −9 M) of L-isoproterenol and Lepinephrin with an increased degree of hypotonic hemolysis and a decreased rate of filtration through standardized paper filters. The receptors in both cell types have many of the characteristics of β-receptors for catecholamines. However, hormone-receptor interaction in the human cell does not lead to an increase in intracellular cyclic AMP concentration, but in the rat cell, hormone-receptor interaction does lead to a significant increase in cylic AMP content. Thus, catecholamine-β-receptor interaction, at least in the human red cell, leads to a change in red cell properties which are not mediated by adenylate cyclase activation. Likewise, prostaglandin E 2, at 10 −12-10 −10 M, causes an increased degree of hypotonic hemolysis and a decreased rate of filtration through standardized paper filters, but it also does not increase the cyclic AMP content of the human erythrocyte but does increase that of the rat erythrocyte. Nevertheless, exogenous cyclic AMP, when added at a concentration of 10 −8 M to washed human erythrocytes, increases the degree of hypotonic hemolysis. Conversely, prostaglandin E 1, at 10 −12-10 −10 M, causes a decreased degree of hypotonic hemolysis and an increased rate of filtration through a standard filter. Both prostaglandin E 2 and the catecholamines decrease the size of a rapidly exchangeable calcium pool, and prostaglandin E 1 increases it.