title: Xenin delays gastric emptying rate and activates the brainstem in mice.
abstract: Xenin, a 25-amino acid gastrointestinal peptide, inhibits feeding by acting through the central nervous system. Gastrointestinal hormones reduce food intake partly by activating the brainstem and inhibiting gastric emptying. Therefore, we hypothesized that xenin delays gastric emptying through the activation of the brainstem cells. To address this hypothesis, we examined the effect of intraperitoneal (i.p.) injection of xenin on gastric emptying rate and brainstem Fos expression in mice. Gastric emptying rate was reduced by about 93% in xenin-treated mice compared to saline-treated control mice. The i.p. xenin injection significantly increased Fos-immunoreactive cells in the nucleus of the solitary tract (NTS) of the brainstem, but not area postrema (AP) and dorsal motor nucleus of the vagus (DMV). These findings support the hypothesis that xenin-induced anorexia is at least partly due to delayed gastric emptying and the activation of the NTS cells.
authors.affiliation: Department of Physiology, University of Manitoba, Winnipeg, MB R3E0J9, Canada.
authors.forename: Eun Ran
authors.initials: ER
authors.lastname: Kim
authors.forename: Tooru M
authors.initials: TM
authors.lastname: Mizuno
mesh_terms: D000818:Animals; D004435:Eating / Q000187:drug effects; D005508:Food Deprivation / Q000502:physiology; D005746:Gastric Emptying / Q000187:drug effects*; D005786:Gene Expression Regulation / Q000187:drug effects; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009496:Neurotensin / Q000494:pharmacology*; D016761:Oncogene Proteins v-fos / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects; D017552:Solitary Nucleus / Q000187:drug effects* / Q000378:metabolism; D018709:Statistics, Nonparametric; D013270:Stomach / Q000033:anatomy & histology
chemical_list: D016761:Oncogene Proteins v-fos; C077659:xenin 25; D009496:Neurotensin