Abstract
To clarify the mechanism involved in age-related fibrotic changes, we investigated immunohistochemical expression of HSP47, type I procollagen, and type I collagen in the salivary glands of Mongolian gerbils aged 1 to 63 months old. Positive reactions to HSP47 and type I procollagen were seen in the fibroblasts and striated duct cells in each glands. Increased fibrous connective tissue and adipose tissue were presented mostly in the parotid gland, less in the submandibular and sublingual gland. The number of fibroblasts expressing HSP47 and type I procollagen increased with age. In the sublingual gland, fibroblast with positive reaction to HSP47 and type I procollagen were observed in the adult and old group. These results indicate that increase of fibroblasts with intracellular HSP47 might be significantly involved in fibrotic changes of salivary gland in aging. Possibility of synthesis and excretion of collagen by striated duct is suggested as well.
