DOI: 10.36347/sjavs.2018.v05i08.003

Pages: 435-440

Abstract: Gastrin-releasing peptide (GRP), which is a 27 amino acid peptide, the mammalian homologue of bombesin, has been identified in various organs including the uterus and placenta. The effects of GRP are mediated by the gastrin-releasing peptide receptor (GRPR), one of the seven transmembrane-spanning G protein-coupled receptors. Although the localization of GRP has been reported in each cell type of the placentae that of GRPR currently remains unknown. Therefore, the aim of the present study was to immunohistochemically examine the localization of GRPR in the bovine uterus and placenta. In the placental tissues, GRPR immunoreactivity was detected in the cytoplasm of uninucleate trophoblast cells (trophoblast cells), but not in binucleate trophoblast giant cells or maternal tissues including the uterine glands. In nonpregnant animals, GRPR was localized in the endometrial epithelial cells of the caruncle only. The differences observed in the localization of GRPR in the chorionic epithelium in the present study demonstrated that GRP directly affected trophoblast cells, but not binucleate trophoblast giant cells differentiated from trophoblast cells. In the present study, the localization of GRPR in the bovine placenta demonstrated is the first in mammalian placentas.