Ascorbate stabilization is stimulated in rho(0)HL-60 cells by CoQ10 increase at the plasma membrane

Long-term treatment with ethidium bromide of HL-60 cells induced a mitochondria-deficient rho degree 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 degree HL-60 cells. Both CoQ10 and NADH-ascorbate free radical reductase of the plasma membrane were increased in rho(0)HL-60 cells compared to parental cells, while NADH-cytochrome c reductase was unchanged. CoQ10 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(0)HL-60 cells and for resistance to oxidative stress.