EXPRESSION AND LOCALIZATION OF HEPATOCYTE GROWTH-FACTOR IN RAT SUBMANDIBULAR-GLAND

By combination of in situ hybridization and immunohistochemical techni ques, the expression of hepatocyte growth factor (HGF) was demonstrate d in the submandibular gland of rats. Both the mRNA signal and immunor eactivity for HGF were localized exclusively to the epithelial cells o f granular convoluted tubules, whereas they were absent from the other components of the submandibular gland. In the granular convoluted tub ule cells, HGF-immunoreactivity was localized to the apical secretory granules, which was further substantiated by immunoelectron microscopy . These results added HGF to the list of many growth factors that are produced in the rat submandibular gland and secreted into the saliva.