Identification of endocrine cells of the stomach that express acid-sensitive background potassium (K(2P)9.1/TASK3) channels.
The family of two-pore domain potassium (K(₂P)) channels is important in setting and controlling the background potassium current of excitable cells. This study examines the localisation of the acid-sensitive channel, K(₂P)9.1 (TASK3), in cells of the gastric mucosa. We observed K(₂P)9.1 immunoreactivity in endocrine cells of the mucosal glands of the guinea-pig, rat and mouse but the channels were not detected in parietal, chief, or mucous cells. K(₂P)9.1 channel immunoreactivity was consistently co-localised with histidine decarboxylase immunopositive enterochromaffin-like (ECL) cells, and with the majority of ghrelin immunoreactive X/A cells. Localisation in somatostatin immunoreactive D cells was rare in the guinea-pig, and did not occur in the stomach of rat, but, in the mouse, K(₂P)9.1 channels were observed in the majority of somatostatin-immunoreactive D cells. Conversely, sections taken from the guinea-pig and mouse stomachs, but not rat stomach, revealed K(₂P)9.1 in gastrin-containing G cells. These results demonstrate the presence of K(₂P)9.1 channels in the entero-endocrine ECL, G and D cell populations of the stomach that regulate acid secretion through the release of histamine, gastrin and somatostatin. K(₂P)9.1 channels were located in the ghrelin X/A cells that regulate food intake.
Needham
Karina
K
Department of Anatomy & Cell Biology, University of Melbourne, Parkville, VIC 3010, Australia. k.needham@unimelb.edu.au
Pontell
Louise
L
Hunne
Billie
B
Thacker
Michelle
M
McHugh
Damian
D
Furness
John B
JB
D000818:Animals; D002478:Cells, Cultured; D055098:Endocrine Cells / Q000166:cytology* / Q000378:metabolism*; D005753:Gastric Mucosa / Q000378:metabolism*; D006168:Guinea Pigs; D007150:Immunohistochemistry; D051379:Mice; D015221:Potassium Channels / Q000378:metabolism*; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013270:Stomach / Q000166:cytology*
D015221:Potassium Channels; C511784:TASK3 protein, mouse