2 TYPES OF MITOCHONDRIA ARE EVIDENCED BY PROTEIN-KINASE-C IMMUNOREACTIVITY IN THE MULLER CELLS OF THE CARP RETINA

The localization of protein kinase C (PKC) was studied immunocytochemi cally in the Muller cells of the carp retina. Electron microscope immu nocytochemistry (using a monoclonal antibody to the alpha and beta iso enzymes of PKC) showed PKC-immunoreactivity mainly inside some mitocho ndria, especially along the mitochondrial cristae whereas other mitoch ondria in the same Muller cells showed no staining. Despite a detailed analysis we did not find any significant morphological difference bet ween labeled and unlabeled mitochondria. These results demonstrate, fo r the first time, the presence of PKC immunoreactivity inside mitochon dria and suggest that individual mitochondria may differ in signal tra nsduction pathway.