Immunohistochemical analysis of cytokeratin expression in dog skin

The expression of cytokeratins and involucrin was analyzed to identify the skin cells which compose the epidermis of dogs. The distribution of cytokeratins and involucrin in normal dog skin was immunohistochemically examined with 27 commercial monoclonal antibodies for human use. Antibodies, No.4. OV-TL12/13, 35betaH11, 4.1.18, CAM5.2, NCL5D3, Ks.13.1, Ks.18.04, Ks.19.1, 170.2.]4 and Ks.20.8 stained hair follicles and/or the sweat gland duct, but not the epidermis. Antibodies, 34betaB4, AE3, 34betaE12. LP34, RCK102, MNF116, AE1, KLI, DE-K10 and DE-K13 reacted with every layer of the epidermis, hair follicles and the sweat gland duct. These results were similar to those reported in the human skin. No positive staining, however, could be detected in the epidermis, hair follicles and the sweat gland duct with commercial antibodies, 6B10, Ks.7.18, Mu146-uc, E3, RCK108 and involucrin. Therefore, immunohistochemical investigation with these commercial antibodies developed for human skin examination might be available for investigating the origin of skin tumors in dogs.