title: Gastric motility in ghrelin receptor knockout mice.
abstract: The aim of this study was to investigate the effects and possible mechanisms of ghrelin receptor (GHS-R) deficiency on gastric motility in GHS-R deficient (Ghsr-/-) mice. Ghsr-/- and control (Ghsr+/+) mice were genotyped by PCR. The percentage of gastric emptying (GE%) was calculated following the intraperitoneal adminis-tration of ghrelin. In vitro, the contractile response of smooth muscle strips to ghrelin and electrical field stimulation (EFS) and the intraluminal pressure change of isolated stomach to carbachol were observed in an organ bath. The staining of nerve cells in the gastric muscle layer was performed by immunofluorescence. Delayed gastric emptying was observed in the Ghsr-/- mice; ghrelin enhanced the GE% in the Ghsr+/+ mice but had no effect on the GE% in the Ghsr-/- mice. In vitro, the response of the strips to ghrelin and EFS and the intraluminal pressure change to cabarchol was reduced in the Ghsr-/- mice. GHS-Rs were predominantly expressed on nerve cells in gastric muscle layers. The number of nerve cells was observed to be decreased in the Ghsr-/- mice. The delayed gastric emptying may relate to the loss of GHS-Rs and the reduction in the number of nerve cells in the gastric muscle layers of the GHS-R-deficient mice.
authors.affiliation: Department of General Surgery, The Affiliated Sixth Hospital of Medical School, Shanghai Jiaotong University, Shanghai 200233, PR China.
authors.forename: Cheng-Guang
authors.initials: CG
authors.lastname: Yang
authors.forename: Wei-Gang
authors.initials: WG
authors.lastname: Wang
authors.forename: Jun
authors.initials: J
authors.lastname: Yan
authors.forename: Jian
authors.initials: J
authors.lastname: Fei
authors.forename: Zhi-Gang
authors.initials: ZG
authors.lastname: Wang
authors.forename: Qi
authors.initials: Q
authors.lastname: Zheng
mesh_terms: D000818:Animals; D005260:Female; D005746:Gastric Emptying / Q000235:genetics; D005753:Gastric Mucosa / Q000378:metabolism; D005769:Gastrointestinal Motility / Q000235:genetics*; D055786:Gene Knockout Techniques; D005838:Genotype; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D054440:Receptors, Ghrelin / Q000235:genetics* / Q000378:metabolism; D013270:Stomach / Q000473:pathology
chemical_list: D054440:Receptors, Ghrelin