Endogenous orexin-A modulates gastric motility by peripheral mechanisms in rats

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Bülbül M., Tan R., Gemici B., Özdem S., Üstünel İ., Acar N., ...Daha Fazla

PEPTIDES, cilt.31, sa.6, ss.1099-1108, 2010 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 31 Sayı: 6
  • Basım Tarihi: 2010
  • Doi Numarası: 10.1016/j.peptides.2010.03.007
  • Dergi Adı: PEPTIDES
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.1099-1108
  • Anahtar Kelimeler: Fasting, Gastric motility, Orexin-A, Preproorexin, MIGRATING MYOELECTRIC COMPLEX, NITRIC-OXIDE SYNTHASE, III-LIKE CONTRACTIONS, DORSAL MOTOR NUCLEUS, ACID-SECRETION, SMALL-BOWEL, EXPRESSION, GHRELIN, GLUCOSE, BRAIN
  • Akdeniz Üniversitesi Adresli: Evet

Özet

Orexin-A (OXA) and orexin receptor type 1 (OX1R) are found in enteric nervous system and smooth muscle cells in the digestive tract. Fasting is a stimulant for OXA synthesis. The aim of the present study was to investigate central and peripheral effects of endogenous OXA on gastric motility. Endogenous OXA synthesis was induced by 36 h fasting. Vagotomy was used to evaluate N.vagus-mediated effects of OXA. Gastric emptying and interdigestive gastric motility were measured by spectrophotometric and manometric methods, respectively. Rats were pretreated with OX1R antagonist SB-334867 prior to measurements. Plasma OXA concentration was assayed with radioimmunoassay while preproorexin (PPO) expression was determined with Western blotting in gastric and hypothalamic tissues. OXA immunoreactivity in antrum was determined with immunohistochemistry. Plasma OXA level, PPO protein expression and OXA immunoreactivity were significantly increased in response to 36 h fasting. Endogenous OXA facilitated gastric emptying and inhibited gastric interdigestive motility. As these effects were abolished with SB-334867, it is likely that gastrokinetic effects of OXA are mediated via OX1R. Vagotomy did not alter OXA-mediated effects. According to current data, OXA is up-regulated both centrally and peripherally upon fasting. Endogenous OXA accelerates gastric emptying while it inhibits interdigestive motility.