Studies on the mechanism of metabolic stimulation in polymorphonuclear leucocytes during phagocytosis II. Presence of the NADPH2 oxidizing activity in a myeloperoxidase-deficient subject

1. 1. The biochemical properties of leucocytes from a myeloperoxidase-deficient subject were compared with those of leucocytes from healthy subjects. 2. 2. Myeloperoxidase-deficient leucocytes respond to phagocytosis of heat-killed bacteria with increased respiration, increased oxidation of glucose through the hexose monophosphate shunt and increased production of H₂O₂ as normal leucocytes do. 3. 3. The ability of granules isolated from myeloperoxidase-deficient leucocytes to oxidize nicotinamide coenzymes was comparable to that of granules isolated from normal leucocytes. 4. 4. The results argue against the hypothesis that oxidation of NADPH₂ in leucocytes is performed by myeloperoxidase.