S-100 protein, a-actin, desmin and vimentin are expressed in bovine skin and third eyelid : an immunohistochemical study

الملخص EN

S-100 protein and cytoskeletal proteins α-actin, desmin and vimentin are cellular proteins that widely used as biomarkers for normal and diseased tissues.

Distribution of these proteins was studied in bovine third eyelid and skin of the ear by the indirect method of immunohist-ochemistry ABC (Avidin Biotin peroxidase Complex).

S-100 protein was not expressed in the epithelium of the third eyelid but was confined to the basal layer of the epidermis.

Dendritic cells in the epidermis and connective tissue cells in both skin and third eyelid were immunopositive for S-100 protein.

Sweat and sebaceous glands were immunonegative for S-100 protein but the glands of the third eyelid were immunopositive ; in addition, hair follicles in skin and chondrocytes in the cartilage of third eyelid exhibited positive staining for the same protein.

α–actin was strongly expressed in the arrector pili muscles, smooth muscle fibers of blood vessels and the tissue surrounding ducts of the superficial glands in third eyelid.

Desmin was constantly expressed in smooth muscle fibers including arrector pili muscles in skin and walls of blood vessels in both skin and third eyelid.

Vimentin was always present in connective tissue cells in both skin and third eyelid however, the epithelium was always immunonegative.

These results revealed a tissue specific distribution of the tested proteins in bovine skin and third eyelid.