Antinociceptive action against @entity694 by brain orexin in conscious XXXX .

@entity22658 @entity344 @entity1744 @entity56 @entity1286 @entity35 @entity694 @entity23908
UNASSIGNED: Increasing evidence has suggested that brain orexins are implicated in a wide variety of physiological functions. With regard to gastrointestinal functions, @entity22658 acts centrally to regulate gastrointestinal functions such as gastric and pancreatic secretion, and @entity344 . Visceral sensation is also known as one of key gastrointestinal functions which are controlled by the central nervous system. Little is, however, known about a role of central orexin in visceral sensation. This study was therefore performed to clarify whether brain orexin may be involved in the process of visceral sensation. Visceral sensation was evaluated by @entity694 -induced abdominal withdrawal reflex (AWR) in conscious @entity35 . Intracisternally administered @entity22658 dose-dependently increased the threshold volume of @entity694 -induced AWR. In contrast, neither intraperitoneal injection of @entity22658 nor intracisternal orexin-B altered the threshold volume. While intracisternal @entity23908 , an orexin 1 receptor antagonist, by itself failed to change the threshold volume, @entity23908 injected centrally completely blocked the @entity1286 -induced antinociceptive action against @entity694 . These results suggest for the first time that @entity22658 specifically acts centrally in the brain to enhance antinociceptive response to @entity694 . We would furthermore suggest that endogenous @entity22658 indeed mediates the antinociceptive effect of @entity1286 on visceral sensation through the orexin 1 receptors. All these evidence might indicate that brain orexin play a role in the pathophysiology of functional @entity344 such as @entity1744 because @entity56 of the gut is considered to play a vital role in the diseases.
