The role of protein kinase C in signal reactions of bovine retinal rod outer segments

The effect of modulators of protein kinase C activity oil Ca2+ translocation in dark-adapted and bleached retinal rod outer segments (ROS) was studied. The activators (1,2-diacyl glycerol and phorbol-12-myristate-13-acetate) and the inhibitor (chelerythrine chloride) of protein kinase C were Shown to stimulate and inhibit the ATP-ependent Ca2+-uptake in dark-adapted retinal ROS, correspondingly. Apparently, this action is due to the influence of protein kinase C on Ca2+-ATPase activity in these vesicular structures. No involvement of modulators of protein kinase C activity oil ATP-dependent Ca2+-uptake in bleached retinal ROS was found. The influence of protein kinase C oil Ca2+-release from retinal ROS was observed. It was shown that the activators and inhibitors of protein kinase C increased the efficiency of this process both in dark-adapted and bleached retinal RQS. The mechanisms of action of the protein kinase C activity modulators on the Ca2+-uptake and Ca2+-release in retinal ROS are discussed.