Immunohistochemical localization of transforming growth factor alpha in the major salivary glands of male and female rats.

The three major salivary glands of normal male and female Fischer 344 rats of different ages were examined for the localization of epidermal growth factor (EGF) and transforming growth factor alpha (TGF alpha) by immunohistochemical staining. EGF was demonstrated only in the granulated convoluted tubule (GCT) cells of the submandibular gland, the results confirming the previous reports, and most abundantly in adult males and pregnant females. TGF alpha stain was localized in all three glands and was found throughout the entire duct system, excluding acinar cells. The myoepithelial cells of the sublingual gland were also reactive with the TGF alpha antibody. The specificity of the staining was confirmed by negative staining reaction with the absorbed antibody and by radio-immunoassay and Western blot methods. This is the first report describing the presence of TGF alpha in the rat salivary glands.