Compound exocytosis of secretory granules containing salivary chromogranin A in granular duct cells in rat submandibular gland: the last study in collaboration with the late Professor Noboru Yanaihara at Yanaihara Institute.

Chromogranin A (CgA) is a member of a family of chromogranins, which are co-stored and co-released with adrenaline and noradrenalin (NAd) in the adrenal medulla in response to stimulation of the splanchnic nerve. Double immunohistochemical staining is carried out by use of antibodies against CgA and 1,4,5-trisphosphate receptor type 2 (IP3R2) on the same sections prepared from the isolated and perfused submandibulllar gland of rat. In the control sections prepared from resting state, an intense IP3R2 immunoreactivity (IR) appeared preferentially at the apical pole of subpopulation of the granulated duct cells, in which CgA-like IR distributed throughout the cytoplasm.

Immunohistochemical localization of chromogranin a in the acinar cells of equine salivary glands contrasts with rodent glands.

We investigated the existence of chromogranin A (CgA) in salivary glands of the horse by Western blotting and enzyme immunoassay (EIA) using an antiserum against a peptide sequence of equine CgA. We also compared its cellular distribution between the horse and rat salivary glands with a tyramide signal amplification immunofluorescence technique. Western blotting gave three significant immunoreactive bands (74, 56 and 48 kDa) in adrenal medulla and three major salivary glands of horses.