Ascorbate stabilization is stimulated in rho degrees HL-60 cells by CoQ(10) increase at the plasma membrane

Long-term treatment with ethidium bromide of HL-60 cells induced a mitochondria-deficient rho degrees cell line, where mitochondrial DNA can not be identified by PCR and cytochrome c oxidase activity was 80% decreased. These cells showed a progressive increase of ascorbate stabilization which was 52% higher in the established rho degrees HL-60 cells. Both CoQ(10) and NADH-ascorbate free radical reductase of the plasma membrane were increased in rho degrees HL-60 cells compared to parental cells, while NADH-cytochrome c reductase was unchanged, CoQ(10) is a component of the ascorbate stabilization activity in the plasma membrane that would provide both a mechanism to deplete the excess of NADH produced in rho degrees HL-60 cells and for resistance to oxidative stress. (C) 1997 Academic Press.