Membrane Potential Changes in Polymorphonuclear Leukocytes of Patients with Chronic Granulomatous Disease

The activation of NADPH oxidase on the plasma membranes of polymorphonuclear leukocytes (PMNL) follows the change of membrane potential. It is thought that the activation of NADPH oxidase is disturbed in the PMNL of patients with chronic granulomatous disease (CGD). The change of membrane potential was examined in the PMNL of normal subjects and patients with CGD, with a lipophilic probe, di-O-C5(3). There was a disturbance in phorbol myristate acetate (PMA) and formyl-methionyl-leucyl-phenylalanine (FMLP)-induced depolarization but not in Ca ionophore A23187-induced depolarization of the PMNL of patients with CGD. A23187-induced depolarization was not always associated with O2- release in normal PMNL. A23187 differed from PMA and FMLP in several aspects of its action on depolarization. It is concluded that only depolarization which couples with O2- release is disturbed in the PMNL of patients with CGD. Increase in extracellular potassium (K) caused PMNL of both normal subjects and CGD patients to depolarize but made them not to release O2-. Otherwise, A23187-induced depolarization was disturbed in PMNL of CGD patients with higher extracellular K concentrations. These findings help to confirm the theory that K efflux on the plasma membrane is disturbed in the PMNL of patients with CGD.