Abstract
HL-60 human promyelocyic leukemia cells were treated with 10-7M 1, 25-dihydroxy vitamin (VD3) for 3-4 days. VD3-treated cells expressed a NADPH-oxidase activity as evidenced by chemiluminescence, cytochrome C reduction and hexose monophosphate shunt activity. Furthermore, cytochrome b that is an essential component of electron transport chain in the respiratory burst appeared in the VD3-treated cells. However, reduced-minus-oxidized spectrum of VD3-treated cells was somewhat different from that of human blood neutrophils. The particulate fraction was prepared from the VD3-treated cells that had been activated with phorbol myristate acetate. NADPH induced luminol mediated chemiluminescence (LMCL) in the fraction. The LMCL required halide and was susceptible to NaN3. No luminescence occurred in the particule fraction of untreated HL-60 cells. It was suggested that NADPH-oxidase dependent H2O2 formaion and H2O2-halide-MPO system were involved in LMCL of the particulate fraction.
