Figure 9. Different action of MB and 2-chlorophenothiazine on mitochondrial complex IV.

(A) Western blots depict the expression of complex IV subunit I (Cox1) in HT-22 cells treated with MB or 2-chlorophenothiazine at the indicated concentrations for 3 days. MB, at concentrations of 10 and 100 nM, increased Cox1expression. 2-Chlorophenothiazine had no effect on Cox1 expression at 10 nM, 100 nM, and 1 µM. (B). Blue native indicated an increase in complex IV activity at 100 nM MB and a decrease in complex IV activity at 1 µM MB corresponding to the increased expression of Cox1. 2-Chlorophenothiazine had no effect on complex IV activity at all concentrations tested.