Hiroyuki Hayashi’s research while affiliated with Kanagawa Dental University and other places

Although several morphological studies of main excretory duct of the submandibular gland have been performed, few reports present immunohistochemical data. Some epithelial cells or basal cells contain dense granules of an array shape by electron microscopic observation. However, the details of granulated cells have not been clarified immunohistochemically. In this study, both protein gene product 9.5 (PGP 9.5) and chromogranin or serotonin immunoreactive cells in the main excretory duct (MED) of the rat submandibular gland were observed. Some nerve endings were also observed among the epithelium of the MED. Therefore, the modifying mechanism of primary saliva in the MED may be regulated by both serotonergic nerve and endocrine cells with serotonin.