Distribution of gamma-glutamyl transpeptidase in human salivary glands: immunohistochemical study using a monoclonal antibody.

We studied in detail the distribution pattern of gamma-glutamyl transpeptidase (gamma-GT) in human salivary glands using a monoclonal antibody (MAb) to human kidney gamma-GT. In the sublingual gland, a strong reactivity of the enzyme was recognized along the luminal and lateral membranes of serous cells. Weak but positive reactivity was noted on the luminal membrane of mucous cells. The intercellular canaliculi in the demilune and luminal surfaces of excretory duct cells were also immunoreactive. In the submandibular gland, a weak reaction was observed on the luminal membrane of intercalated duct cells and striated duct cells. Faint reactivity was seen on the luminal membrane of striated duct cells of the parotid gland. No reaction was observed in serous cells of the parotid gland. The immunoreaction in the sublingual gland was stronger than that in submandibular or parotid glands.