Localization of luteinizing-hormone releasing hormone binding sites in the gastric mucosa of suckling rats.
Luteinizing-hormone releasing hormone (LHRH) is a hypothalamic and milk-borne hormone that inhibits the cell proliferation of gastric epithelium in developing rats, although the mechanism of such action is unknown. We investigated the presence of binding sites for LHRH in the stomach of suckling rats after the injection of the hormone. Immunofluorescence at the confocal microscopy level revealed that LHRH binds to gastric cells, being particularly abundant over the gland. Different fluorescent lectins were used to identify gastric cell types and determine which were labeled by the hormone. Colocalization studies in these double-labeling experiments showed that LHRH staining colocalizes with parietal cells, suggesting the presence of binding sites in these cells. The three-dimensional (3-D) reconstruction of isolated parietal cells revealed the localization of the signal, which appears to be in the membrane of the canalicular region. These results suggest that there are binding sites for LHRH in the gastric epithelium, specifically in parietal cells, and they might play a role in the control of cell proliferation during suckling.
Gama
P
P
Department of Histology and Embriology, ICB I, University of São Paulo, São Paulo, Brazil 05508-900. patgama@usp.br
Alvares
E P
EP
D000818:Animals; D000833:Animals, Suckling / Q000378:metabolism*; D001665:Binding Sites; D005753:Gastric Mucosa / Q000166:cytology / Q000378:metabolism*; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism* / Q000493:pharmacokinetics; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007150:Immunohistochemistry; D018613:Microscopy, Confocal; D010295:Parietal Cells, Gastric / Q000378:metabolism; D051381:Rats / Q000378:metabolism*; D017208:Rats, Wistar; D013194:Staining and Labeling; D014018:Tissue Distribution
D007987:Gonadotropin-Releasing Hormone