Localization of chromogranin A and B, beta-endorphin and enkephalins in the submandibular glands of mice.

The localization of chromogranin A and B, beta-endorphin, met-enkephalin and leu-enkephalin was immunocytochemically investigated in the submandibular salivary gland (SMG) and pancreas of male mice using different antibodies. Procedures were carried out with different immunocytochemical methods, such as peroxidase-antiperoxidase and indirect immunofluorescence methods, visualized with diamino-benzidine, 4-chloro-1-naphthol and FITC stainings. Chromogranin A immunoreactivity was located in the granular convoluted tubule cells (GCT), whereas chromogranin B immunoreactivity was located in some of the solitary cells scattered around the acini, but not in GCT of SMG. In the pancreas, different localizations were observed between chromogranin A and B. Beta-endorphin and met-enkephalin immunoreactivities were also located in GCT, but in the striated duct cells as well. However, met-enkephalin, but not beta-endorphin, immunoreactivity was found in the nerves around the duct system. Our results strongly suggest that chromogranin A, but not chromogranin B, may be useful as a means to differentiate the cells in the duct system of the SMG responsible for production of biologically-active factors.