IMMUNOHISTOCHEMICAL DISTRIBUTION OF KERATIN PROTEINS IN FELINE TISSUES

The immunohistochemical distribution pattern of some keratin intermedi ate filament proteins has been analysed in a wide range of formalin fi xed, paraffin embedded feline tissues using one polyclonal and two mon oclonal antibodies raised against human keratins by means of the avidi n-biotin-peroxidase complex technique. Only the epithelial and mesothe lial cells were stained by the three antibodies, but differences in th eir corresponding staining pattern were noticed. The staining reaction of the polyclonal antibody raised against human skin keratin was foun d in both stratified and complex epithelia, while that of the monoclon al antibody which recognizes human keratins 8 + 18 + 19 of the Moll ca talogue (NCL-5D3) was restricted to some simple epithelia. The stainin g reaction of the monoclonal antibody which reacts with human keratins 5 + 8 of the Moll catalogue (RCK-102) covered the widest spectrum of feline epithelial tissues analysed, including stratified, complex and simple epithelia. These staining patterns of feline tissues are basica lly similar with respect to those of corresponding tissues in other ma mmalian species, although some differences were also noticed and some obvious epithelial tissues were not stained. This study confirms the b road interspecies cross-reactivity of keratin proteins antibodies and demonstrates their capability to differentiate between various types o f feline epithelia and some epithelial compartments.