PURPOSE:To verify existance of a-,~-,and 3'-protein kinase C(PKC)subspecies and their localization in rabbit retina. METHODS: Using an immunohistoehemical technique with mono- elonal antibodies against PKC isozymes- I (a),-I[ (13),and -~[ (Y) to characterize the distribution of PKC in rabbit retina. RESULTS:There is a positive immunostaining for a-,13-,and ~-PKC in rabbit retina. The immunoreactivity of a-PKC was observed mainly in the bipolar cells of inner nuclear layer and the outer segments of photorecptors. The positive immunostaining of 13-PKC could be seen in the ganglion cells,inner plexiform layer,inner nuclear layer,and the outer segments of photoreceptors. A diffuse and weak staining of Y-PKC is recognized in the ganglion cell layer,inner plexifrom layer,inner nuclear layer, and the outer segments of photoreceptors. CONCLUSION:The protein kinase C sub- speeies-a,-~,and-'Y are present in retina which is a part of the central nervous system