Immunolocalization of endothelin-B receptor in mouse intestinal tract.
The endothelin-B (ETB) receptor is a G-protein-coupled receptor that binds endothelin ligands and is essential for the development of epidermal melanocytes and enteric neurons. Recent reports indicate that ETB is localized to nuclei in cardiac ventricular myocytes, although it has been thought that ETB is localized mainly on the plasma membrane. It remains unknown, however, whether this unique distribution of ETB occurs in other tissues. To elucidate the subcellular distribution of ETB in the intestine, we performed immunofluorescence of ETB in mouse intestine using a specific antibody. ETB-like immunoreactivity was detected in both the mucosal and muscle layers. In the mucosal layer, villous epithelial cells, stromal cells of the lamina propria, and cryptic cells were immunostained. Subcellularly, ETB is localized mainly to the nuclei of villous epithelial cells. In the muscle layer, immunoreactivity of ETB was localized to the myenteric plexus. These findings suggest that ETB may function as an "intracrine" receptor for intracellular endothelin ligands in villous epithelial cells and may regulate intestinal function.
Takizawa
Satoshi
S
Institute for Biological Resources and Functions, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan.
Uchide
Tsuyoshi
T
Kozakai
Takaharu
T
Adur
Javier
J
Quan
Jiexia
J
Saida
Kaname
K
D000818:Animals; D005455:Fluorescent Antibody Technique; D007082:Ileum / Q000737:chemistry* / Q000294:innervation; D007413:Intestinal Mucosa / Q000737:chemistry; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009130:Muscle, Smooth / Q000737:chemistry; D009197:Myenteric Plexus / Q000737:chemistry; D044023:Receptor, Endothelin B / Q000032:analysis*; D012007:Rectum / Q000737:chemistry* / Q000294:innervation
D044023:Receptor, Endothelin B