Immunohistochemical localization of cathepsin D in ocular tissues.
Cathepsin D has been believed to play an important role in the catabolism of protein in various tissues. In retinal pigment epithelium, cathepsin D degrades rod outer segments and rhodopsin into glycopeptides. To our knowledge, no reports have described the immunohistochemical localization of cathepsin D in whole ocular tissues. We investigated the reaction of bovine, rat, and human eyes with a polyclonal antibody to cathepsin D from bovine spleen. Cathepsin D immunoreactivity was observed in the cytoplasm of the following cells: epithelium and endothelium of the cornea; keratocytes; pigmented and nonpigmented epithelium of the ciliary body; epithelium and cortex of the lens; epithelium and sphincter and dilator muscles of the iris; Müller cells; ganglion cells and pigment epithelium of the retina; and endothelium of various vessels. Positively stained ocular tissues were believed to have a high activity of protein catabolism. Since cathepsin D was closely associated with phagosomes in retinal pigment epithelium, we concluded that cathepsin D probably contributes to the physiologic degradation of rod outer segments.
Department of Ophthalmology, Tohoku University School of Medicine, Sendai, Japan.
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Yamada
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Hara
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Tamai
D000328:Adult; D000818:Animals; D000918:Antibody Specificity / Q000276:immunology; D015153:Blotting, Western; D002402:Cathepsin D / Q000032:analysis*; D002417:Cattle; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005123:Eye / Q000032:analysis*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D010857:Pigment Epithelium of Eye / Q000032:analysis; D011817:Rabbits; D051381:Rats; D011922:Rats, Mutant Strains; D013154:Spleen / Q000032:analysis
D002402:Cathepsin D