NADPH and NADH serve as electron donor for the superoxide-generating enzyme in tilapia (Oreochromis niloticus) neutrophils.

NADPH oxidase has been identified as the superoxide-generating enzyme in fish neutrophils. To clarify the electron-donating ability of this enzyme, we examine the requirement of NADPH as the electron donor in superoxide generation in tilapia (Oreochromis niloticus) neutrophils using CLA-dependent chemiluminescence (CL). Phorbol ester-induced CL responses were terminated upon the addition of a detergent, Renex-30. The addition of graded amounts of NADPH or NADH restored the CL in a dose-dependent manner. The restoration of CL was completely eliminated by superoxide dismutase, suggesting that the restored CL was due to superoxide generation. NADPH tended to have a greater effect than NADH on the CL responses of tilapia neutrophils.