Figure 4. PKC immunoreactivity in the smooth muscle layer of the retinal arteries. Representative examples showing phosphorylated PKCα, PKCβ1, and PKCβ2 immunoreactivity in the retinal arteries following ischemia and 20 h of reperfusion. Double staining with smooth muscle actin, a smooth muscle marker, showed colocalization with phosphorylated PKC in the smooth muscle layer (arrows). Note that the colocalization was most apparent for phosphorylated PKCα.