Central orexin-A increases gastric motility in rats

作者：Bulbul Mehmet; Babygirija Reji; Ludwig Kirk; Takahashi Toku^*

来源：Peptides, 2010, 31(11): 2118-2122.

DOI：10.1016/j.peptides.2010.07.014

• Hypocretin
• Restraint stress
• Dorsal motor nucleus of vagi (DMV)
• Corticotropin releasing factor (CRF)
• Gastric emptying
• Antro pyloric coordination

Orexin receptor type-1 (OX1R) is expressed in the dorsal motor nucleus of vagi (DMV) Although orexin-A (OXA) plays an important role in mediating stress responses It remains unclear how central OXA regulates gastric dysmotility Induced by stress Acute restraint stress (ARS) delays solid gastric emptying via the central corticotropin releasing factor (CRF) and peripheral autonomic neural pathways We have previously shown that ARS impairs postprandial antro-pyloric coordination and delays solid gastric emptying in rats We also showed that postprandial gastric contractions were augmented in response to ARS in rats However the mechanism of augmented postprandial gastric contractions induced by ARS remains unclear We tested the hypothesis that augmented gastric motility induced by ARS is mediated via the central OX1R We also assessed the role of endogenous OXA in the mediation of gastric motility under non-stressed conditions in conscious rats A strain gauge transducer was implanted on the antrum to record postprandial gastric motility To investigate whether endogenous OXA is Involved in ARS-Induced augmented gastric motility selective OX1R antagonist SB-334867 (16 mu g) was administered intracere-broventricularly (icy) Icv-injection of SB-334867 abolished the augmented gastric contractions induced by ARS Spontaneous postprandial gastric motility was enhanced by icv-injection of OXA (10 mu g) while it was attenuated by icy-injection of SB-3334867 It is suggested that central OXA mediates augmented gastric motility induced by ARS in rats Central OXA also modulates postprandial gastric contractions in non-stressed conditions Published by Elsevier Inc

• 出版日期2010-11