Effect of orexin-a on ischemia-reperfusion-induced gastric damage in rats.
BACKGROUND
Orexins are involved in the regulation of sleeping behavior and energy homeostasis, and they are also implicated in the regulation of gastrointestinal functions. Previous reports have demonstrated the expression of orexin receptors in the gastrointestinal system. The aim of this study was to investigate the gastroprotective effect of orexin-A in ischemia-reperfusion-induced gastric mucosal injury.


METHODS
The gastric ischemia-reperfusion model was established by clamping the celiac artery for 30 min and reperfusing for 60 min. Orexin-A was administered in doses of 500 pmol.kg(-1).min(-1) by infusion throughout the ischemia-reperfusion period. The mean lesion area, gastric prostaglandin E2 and mucus content, myeloperoxidase activity, and production of thiobarbituric acid reactive substances were measured.


RESULTS
Orexin-A significantly attenuated the ischemia-reperfusion-induced gastric lesions and also decreased myeloperoxidase activity and the thiobarbituric acid reactive substances content in gastric mucosa of rats exposed to ischemia-reperfusion. However, the decline in gastric prostaglandin E2 and mucus content was not restored by orexin-A treatment.


CONCLUSIONS
Orexin-A exhibited a gastroprotective effect against ischemia-reperfusion-induced lesions by decreasing neutrophil activation and lipid peroxidation.
Bülbül
Mehmet
M
Department of Physiology, Faculty of Medicine, Akdeniz University, 07070, Antalya, Turkey.
Tan
Ruken
R
Gemici
Burcu
B
Ongüt
Gözde
G
Izgüt-Uysal
V Nimet
VN
D000818:Animals; D015232:Dinoprostone / Q000378:metabolism; D005260:Female; D005753:Gastric Mucosa / Q000187:drug effects* / Q000473:pathology; D047908:Intracellular Signaling Peptides and Proteins / Q000494:pharmacology*; D015227:Lipid Peroxidation / Q000187:drug effects; D009093:Mucus / Q000187:drug effects / Q000378:metabolism; D009479:Neuropeptides / Q000494:pharmacology*; D018377:Neurotransmitter Agents / Q000494:pharmacology*; D018375:Neutrophil Activation / Q000187:drug effects; D000068797:Orexins; D009195:Peroxidase / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000517:prevention & control*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D018377:Neurotransmitter Agents; D000068797:Orexins; D017392:Thiobarbituric Acid Reactive Substances; D009195:Peroxidase; D015232:Dinoprostone