ABSTRACT
We contribute the first immunohistochemical study of MT1 melatonin receptor in Warthin's tumor and normal parotid gland. All 14 Warthin's tumors studied showed intense cytoplasmic positivity for MT1 receptor in all cylindrical epithelial cells lining spaces and a less intense positivity in basal cells. The lymphoid component accompanying the tumor was always negative for MT1 receptor. The parotid structure surrounding the tumor showed intense cytoplasmic positivity in all cells lining excretory ducts (lobar and lobulillar), with a lesser and focal positivity in cells of the acinar component. The biological activity of MT1 receptor in epithelial cells lining parotid excretory ducts may resemble its activity in Warthin's tumor cells. Hence, we propose Warthin's tumor as a useful positive control in immunohistochemical studies of MT1 melatonin receptor.
Subject(s)
Adenolymphoma/metabolism , Receptor, Melatonin, MT1/biosynthesis , Adenolymphoma/genetics , Adenolymphoma/pathology , Adult , Epithelial Cells/metabolism , Epithelial Cells/pathology , Female , Humans , Immunohistochemistry , Male , Middle Aged , Parotid Gland/metabolism , Parotid Gland/pathology , Receptor, Melatonin, MT1/genetics , Receptor, Melatonin, MT1/metabolismABSTRACT
AIM: To analyze and compare the expression of MTNR1A receptor in normal and pathological major and minor salivary glands. MATERIALS AND METHODS: Twenty samples of major and minor salivary glands and 10 with Warthin's tumor were studied. Expression of the MTNR1A receptor (goat polyclonal antibody raised against a peptide mapping at the N-terminus of MEL-1A R of human origin) was analyzed. RESULTS: The excretory ducts of major salivary glands demonstrated intense intracytoplasmic positivity but scant cytoplasmic membrane positivity for MTNR1A. The studied Warthin's tumors showed intense cytoplasmic positivity for MT1 receptor in all cylindrical epithelial cells lining spaces and a less intense positivity in basal cells. The lymphoid component accompanying the tumor was negative for MT1 receptor. CONCLUSION: Intense intracytoplasmic positivity for the MTNR1A receptor in the excretory ducts of human major and minor salivary glands and Warthin's tumor was found. The intense expression of MTNR1A receptors observed in this study in the excretory ducts of major and minor salivary glands may be related to salivary regulation.
