抄録
It is well known that neuropeptide Y (NPY), a potent appetite enhancer, controls gastric motility. The administrations of NPY into the dorsal motor nucleus of the vagus facilitated antral motility via Y1 receptors. The intracerebroventricular injections of NPY delayed gastric emptying via Y2 receptors. Thus, NPY is involved in the central control of gastric motor functions. However, relationship between NPY and gastric reservoir functions has not been clarified. Our previous research revealed that intracisternal administrations of orexin-A facilitated distal stomach motility and relaxed the proximal stomach. Therefore, NPY may also induce relaxation of the proximal stomach to facilitate reservoir function. To demonstrate it, the effects of the intracisternal administration of NPY on the proximal stomach motility were examined in urethane-chloralose anaesthetized rats. The intracisternal administration of NPY (3 nmol) induced relaxation of the proximal stomach lasting for more than 30 min. The intragastric pressure decreased, dose-dependently. The administration of [Leu31, Pro34]NPY (a Y1 receptor agonist) induced relaxation more potent than NPY. The administration of NPY13-36 (a Y2 receptor agonist), did not induce any response in the proximal stomach. Thus, NPY induced relaxation of the proximal stomach via Y1 receptors in the CNS. [Jpn J Physiol 54 Suppl:S197 (2004)]
