抄録
Relaxin is a short circulating peptide hormone, and the major stored and circulatory form in humans is relaxin-2, generally known to have hormogenic functions and to act as an antifibrotic factor during childbirth in females. Relaxin is also expressed in mammary gland tissue and its tumors, suggesting association with tumorigenesis and development in exocrine tissues. In addition, leucine-rich repeat containing G protein-coupled receptors（LGR）7 and LGR8 are known to be receptors for relaxin. To understand the biological role of relaxin, it is necessary to determine the distribution pattern of both relaxin and its related receptors. Therefore, we performed a preliminary immunohistochemical analysis of relaxin and the receptors in salivary gland tumors comprising pleomorphic adenomas, Warthin tumors, adenoid cystic carcinomas, mucoepidermoid carcinomas and submandibular gland tissues.
The immunohistochemical findings showed positive immunoreactivity for relaxin-2 in the ductal, myoepithelial and/or basaloid cells in pleomorphic adenomas, Warthin tumors, adenoid cystic carcinomas, mucoepidermoid carcinomas, and in duct, myoepithelial and serous acinar cells in the submandibular glands.
These results suggest that localization and binding of relaxin-2 and receptors such as LGR7 and LGR8 are associated with ductal and tubular growth of the tumors, as well as the maintenance of duct formation, in salivary gland tumors and submandibular gland tissues.
