The Sweetener-Sensing Mechanisms of the Ghrelin Cell.
Carbohydrate administration decreases plasma levels of the 'hunger hormone' ghrelin. The ghrelin cell is co-localized with the sweet taste receptor subunit, TAS1R3, and the gustatory G-protein, gustducin, both involved in the sensing of sweeteners by entero-endocrine cells. This study investigated the role of gustducin-mediated sweet taste receptor signaling on ghrelin secretion in a gastric ghrelinoma cell line, tissue segments and mice. The monosaccharide d-glucose and low-intensity sweetener oligofructose (OFS) decreased (p < 0.001) ghrelin secretion while the high-intensity sweetener sucralose increased (p < 0.001) ghrelin secretion in vitro. These effects were not mediated via the sweet taste receptor or glucose transporters (the sodium-dependent glucose cotransporter SGLT-1 and GLUT2). The effect of these compounds was mimicked ex vivo in gastric and jejunal segments from both wild type (WT) and α-gustducin knockout (α-gust-/-) mice. In vivo, the sensing of d-glucose was polarized since intragastric but not intravenous administration of d-glucose decreased (p < 0.05) ghrelin levels in an α-gustducin independent manner which involved inhibition of duodenal ghrelin release. In contrast, neither OFS nor sucralose affected ghrelin secretion in vivo. In conclusion, α-gustducin-mediated sweet taste receptor signaling does not play a functional role in the sensing of carbohydrates, or low- or high-intensity sweeteners by the ghrelin cell.
['Steensels|Sandra|S|', 'Vancleef|Laurien|L|', 'Depoortere|Inge|I|']
D000818:Animals D045744:Cell Line, Tumor D005753:Gastric Mucosa D005786:Gene Expression Regulation D054439:Ghrelin D007583:Jejunum D008297:Male D051379:Mice D008810:Mice, Inbred C57BL D018345:Mice, Knockout D012333:RNA, Messenger D015398:Signal Transduction D013549:Sweetening Agents D015293:Transducin
ghrelin sweet taste receptor gustducin sweeteners glucose