Grider John R, Langdon Lea E
Department of Physiology and Medicine, Medical College of Virginia Campus, Virginia Commonweath University, Richmond, Virginia 23298, USA.
Am J Physiol Gastrointest Liver Physiol. 2003 Dec;285(6):G1139-46. doi: 10.1152/ajpgi.00082.2003. Epub 2003 Aug 14.
The physiological role of neuropeptide Y (NPY) and of specific NPY receptors in regulating the intestinal peristaltic reflex was examined in three-compartment flat-sheet preparations of rat colon. Graded muscle stretch or mucosal stimulation applied to the central compartment inhibited NPY release in the orad compartment where ascending contraction was measured. NPY and the Y1-receptor agonist [Leu31, Pro34]NPY inhibited, whereas the selective Y1-receptor antagonist BIBP 3226 augmented ascending contraction and substance P (SP) release in the orad compartment induced by muscle stretch or mucosal stimulation. Neither agonist nor antagonist had any effect on descending relaxation or VIP release in the caudad compartment. The Y2-receptor agonist NPY13-36 and antagonist BIIE 0246 had no effect on peptide release or mechanical response. The results indicate that suppression of a tonic inhibitory influence of NPY neurons on excitatory neurotransmitter release contributes substantially to the orad contractile phase of the peristaltic reflex. The effect of NPY on neurotransmitter release is mediated by Y1 receptors.
在大鼠结肠的三室平板制备物中研究了神经肽Y（NPY）及特定NPY受体在调节肠蠕动反射中的生理作用。施加于中间隔室的分级肌肉牵张或黏膜刺激可抑制口侧隔室中NPY的释放，在该口侧隔室中测量升支收缩。NPY和Y1受体激动剂[Leu31, Pro34]NPY可抑制，而选择性Y1受体拮抗剂BIBP 3226可增强由肌肉牵张或黏膜刺激诱导的口侧隔室中的升支收缩和P物质（SP）释放。激动剂和拮抗剂对尾侧隔室中的降支舒张或血管活性肠肽（VIP）释放均无影响。Y2受体激动剂NPY13 - 36和拮抗剂BIIE 0246对肽释放或机械反应均无影响。结果表明，NPY神经元对兴奋性神经递质释放的紧张性抑制作用的抑制在很大程度上有助于蠕动反射的口侧收缩期。NPY对神经递质释放的作用由Y1受体介导。
