Localization of Chromogranins, Non-neuron-specific Enolase, and Different Forms of Somatostatins in the Submandibular Salivary Glands of Mice

The localizations of chromogranins A, B, and C, neuron-specific enolase (NSE, γγ-type) and non-NSE (αα-type), and different forms of somatostatins were immunocytochemically identified. The localizations were compared with those of epidermal growth factor (EGF) and nerve growth factor (NGF) in the submandibular salivary glands (SMG) of male mice at five to six weeks of age, with use of a variety of antibodies and the peroxidase-antiperoxidase (PAP) and avidin-biotin complex (ABC) detection methods. In the SMG of male mice, the major chromogranin present was chromogranin A, whereas chromogranins B and C were not detected at these ages by either method. Chromogranin Alike immunoreactivity was located in the granular convoluted tubule (GCT) cells of the SMG, whereas non-NSE immunoreactivity was observed throughout the duct system and in some acinar-associated cells. NSE was not detected in any part of the SMG. The distribution of chromogranin A and somatostatins in the GCT cells was similar to that of EGF and NGF. Our results strongly suggest that chromogranin A and somatostatins, but not chromogranin B or C, may be useful as a means of differentiation of the cells in the duct system of the SMG responsible for the production of biologically-active factors.