Endocrine and exocrine secretion of leptin by the gastric mucosa.
Leptin is a hormone that plays important roles in nutritional status and in obesity. By means of immunocytochemistry, two populations of leptin-secreting cells were found in the lower half of the gastric mucosa. One consists of numerous large cells located around the gastric pits, the Chief epithelial cells, whereas the second refers to much smaller cells, strongly stained, few in number, and scattered between the gastric pits, the endocrine cells. By double immunostaining, leptin and pepsinogen were colocalized in the Chief cells, whereas the endocrine cells were positive only for leptin. Immunoelectron microscopy showed that leptin is present along the rough endoplasmic reticulum-Golgi-granules secretory pathways of the Chief and endocrine cells. On the other hand, leptin-receptor (long and short forms) immunolabelings, although absent in the gastric epithelial cell plasma membranes, were present in enterocytes at the level of their apical and basolateral membranes. Duodenal, jejunal, and ileal enterocytes displayed similar labelings for the leptin receptor. Thus, exocrine and endocrine secretions of leptin together with the presence of leptin receptors on enterocyte plasma membranes constitute a gastroenteric axis that coordinates the role played by leptin in the digestive tract.
Département de Pathologie et Biologie Cellulaire, Université de Montréal, C.P. 6128, Succursale Centre Ville, Montréal, Québec, Canada H3C 3J7.
Philippe G
PG
Cammisotto
Christian
C
Renaud
Diane
D
Gingras
Edgard
E
Delvin
Emile
E
Levy
Moïse
M
Bendayan
D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D019872:Chief Cells, Gastric / Q000378:metabolism / Q000648:ultrastructure; D020895:Enterocytes / Q000378:metabolism; D019858:Enteroendocrine Cells / Q000378:metabolism* / Q000648:ultrastructure; D005753:Gastric Mucosa / Q000378:metabolism* / Q000648:ultrastructure; D007150:Immunohistochemistry; D007421:Intestine, Small / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D020738:Leptin / Q000378:metabolism*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D011956:Receptors, Cell Surface / Q000378:metabolism; D054411:Receptors, Leptin
D020738:Leptin; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin