Occurrence of adenyl cyclase activity in human erythrocytes.

Abstract

Red cell ghosts from healthy volunteers and from patients suffering from haemopoietic or haemolytic disorders were differentiated with respect to their basal, sodium fluoride- and isoproterenol-stimulated adenyl cyclase activities; it was investigated whether adenyl cyclase activities are correlated with the reticulocyte counts in the respective blood samples. In the experiments presented, it has been established for the first time that significant adenyl cyclase activity is present in ghosts from human red blood cells. In patients with pernicious anaemia, both reticulocyte counts and sodium fluoridestimulated adenyl cyclase activities were found to be enhanced during treatment with cyanocobalamine. In patients with haemolytic diseases (reticulocyte counts about 10%) adenyl cyclase activities did not differ from those found in healthy volunteers (about 1% reticulocytes). In ghost preparations from patients with chronic renal insufficiency, sodium fluoride- and isoproterenol-stimulated adenyl cyclase activities were slightly depressed. The possible significance of these findings is discussed.