Immunohistochemical analysis of Cox Va and acrolein. (A-F) Effects of 670 nm light treatment on the metabolic status and oxidative stress profiles of the mouse retinas following exposure to 10d and 14d of hyperoxic exposure were examined by immunohistochemical staining. Cryosectioned retinas from the inferior region of the NT and Tr groups were labelled with marker for mitochondrial metabolism, Cox Va (green) and indicator of oxidative stress, acrolein (red). Compared to 0d control retina (A), Cox Va labelling patterns (green) in the 10dNT and 14dNT were disrupted (B-C, green) but not in the 10dTr and 14dTr groups (E-F, green). Exposure to hyperoxia caused a significant increase in the acrolein expression in 10dNT and 14dNT retinas (B-C, red) compared to 0d control (D). The acrolein labelling was also present in the 10dTr and 14dTr groups but the intensity was much lower than the NT retinas (E-F, red). Scale bar 25 μm.