Detection of an Intermediate Filament Protein in the Pancreas and Mandibular Salivary Gland of the Goat (Capra hircus): An Immunocytochemical Study

Abstract

The centroacinar cells (CACs) are a specialized ductal pancreatic cell. Recently, it has been revealed that such cells showed a progenitor function in the pancreas of adult mouse and zebrafish. However, no information about its occurrence in other exocrine glands specially in farm animals. Cytokeratins immunohistochemistry was used to detect ductal segments of the submandibular glands and the pancreas including CACs in human and rat. In the present study, the detection of cytokeratins in the normal goat pancreas (a serous type gland) and mandibular salivary gland (a mixed type gland, consisted of mucous tubules capped with serous demilunes) was investigated using a standard immunoperoxidase technique on paraffin sections. In the goat pancreas and mandibular salivary gland, cytokeratins were found in all duct cells including the CACs of the pancreas. Interestingly in the mandibular salivary glands, some immunoreacted cells with immunopositive cytoplasmic extensions were frequently observed between the cytoplasm of the mucous cells, especially near the lumina of the mucous tubules. We postulate that these cells could be centroacinar- like cells. Therefore, from these findings, it can be concluded that these cells could provide a supportive cytoskeleton to maintain cellular shape and avoid the collapse of the mucous cells during mucous secretion. Additionally, a regenerative function for such cells could be hypothesized. Furthermore, the keratin demonstration could be used as a marker for ductal cells and is a useful aid in the detection of lesions derived from gland ductal cells in goat. Further research is necessary to investigate the expression of keratins in caprine glandular tumors as well as the regenerative ability of these centroacinar- like cells in goat mandibular salivary glands injury.