BACKGROUND: Ghrelin, a growth-hormone-releasing peptide, has two major molecular forms: acylated (acyl) and desacylated (desacyl). Recent studies suggest different roles for these two forms. In the present study, we compared desacyl and acyl ghrelin with regard to acid secretion and histamine production in the rat stomach. METHODS: We performed in vivo experiments using gastric lumen-perfused rats. The effects of the two forms of ghrelin on gastrin (gastrin-17)-stimulated acid secretion were also examined. Furthermore, to examine the effects of ghrelin on histamine production, histidine decarboxylase messenger ribonucleic acid in the gastric corpus mucosa was measured by reverse transcription-polymerase chain reaction. RESULTS: Intravenous administration of acyl ghrelin at 20 μg/kg increased gastric acid secretion to 4.8 times greater than control levels. However, desacyl ghrelin had no effect on acid secretion, even at 200 μg/kg. Acyl ghrelin enhanced gastrin-stimulated acid secretion while desacyl ghrelin did not. Vagotomy markedly inhibited the enhancement of gastrin-stimulated acid secretion by acyl ghrelin. Acyl ghrelin increased histidine decarboxylase messenger ribonucleic acid concentration by 2.3 times compared with basal levels at 1 h after administration and by 2.7 times at 2 h after administration; desacyl ghrelin had no such effect. Synergism between acyl ghrelin and gastrin was seen regarding histidine decarboxylase messenger ribonucleic acid concentration. CONCLUSIONS: The results indicate that acyl ghrelin stimulates gastric acid secretion via a mechanism involving activation of the vagus nerve and histamine release and synthesis and that desacyl ghrelin has no action on gastric acid secretion. Furthermore, the results demonstrate synergism between gastrin and acyl ghrelin in terms of gastric acid secretion via a mechanism involving histamine release and synthesis.
BACKGROUND:Ghrelin, a growth-hormone-releasing peptide, has two major molecular forms: acylated (acyl) and desacylated (desacyl). Recent studies suggest different roles for these two forms. In the present study, we compared desacyl and acyl ghrelin with regard to acid secretion and histamine production in the rat stomach. METHODS: We performed in vivo experiments using gastric lumen-perfused rats. The effects of the two forms of ghrelin on gastrin (gastrin-17)-stimulated acid secretion were also examined. Furthermore, to examine the effects of ghrelin on histamine production, histidine decarboxylase messenger ribonucleic acid in the gastric corpus mucosa was measured by reverse transcription-polymerase chain reaction. RESULTS: Intravenous administration of acyl ghrelin at 20 μg/kg increased gastric acid secretion to 4.8 times greater than control levels. However, desacylghrelin had no effect on acid secretion, even at 200 μg/kg. Acyl ghrelin enhanced gastrin-stimulated acid secretion while desacylghrelin did not. Vagotomy markedly inhibited the enhancement of gastrin-stimulated acid secretion by acyl ghrelin. Acyl ghrelin increased histidine decarboxylase messenger ribonucleic acid concentration by 2.3 times compared with basal levels at 1 h after administration and by 2.7 times at 2 h after administration; desacylghrelin had no such effect. Synergism between acyl ghrelin and gastrin was seen regarding histidine decarboxylase messenger ribonucleic acid concentration. CONCLUSIONS: The results indicate that acyl ghrelin stimulates gastric acid secretion via a mechanism involving activation of the vagus nerve and histamine release and synthesis and that desacylghrelin has no action on gastric acid secretion. Furthermore, the results demonstrate synergism between gastrin and acyl ghrelin in terms of gastric acid secretion via a mechanism involving histamine release and synthesis.
Authors: Y Date; M Kojima; H Hosoda; A Sawaguchi; M S Mondal; T Suganuma; S Matsukura; K Kangawa; M Nakazato Journal: Endocrinology Date: 2000-11 Impact factor: 4.736
Authors: Cecilia T de Barros; Alessandra C Rios; Thaís F R Alves; Fernando Batain; Kessi M M Crescencio; Laura J Lopes; Aleksandra Zielińska; Patricia Severino; Priscila G Mazzola; Eliana B Souto; Marco V Chaud Journal: Int J Mol Sci Date: 2020-08-19 Impact factor: 5.923
Authors: Mario Perelló; María P Cornejo; Pablo N De Francesco; Gimena Fernandez; Laurent Gautron; Lesly S Valdivia Journal: IBRO Neurosci Rep Date: 2022-03-12