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Neuropeptide Y Inhibits the Migrating Myoelectric Complex and Delays Small Intestinal Transit in Rats
Author(s) -
Hellström Per M.,
Johansson Catja
Publication year - 1989
Publication title -
neurogastroenterology and motility
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.489
H-Index - 105
eISSN - 1365-2982
pISSN - 1350-1925
DOI - 10.1111/j.1365-2982.1989.tb00143.x
Subject(s) - neuropeptide y receptor , phentolamine , endocrinology , migrating motor complex , medicine , small intestine , guanethidine , jejunum , peptide yy , duodenum , pylorus , chemistry , propranolol , neuropeptide , stomach , stimulation , receptor
The effect of neuropeptide Y (NPY) on myoelectric activity of the small intestine was related to transit of a radioactive marker in fasted conscious rats. Myoelectric activity was recorded with bipolar electrodes implanted 5, 20, and 35 em distal to pylorus. A radioactive marker was administered luminally in the duodenum immediately after an activity front of a migrating myoelectric complex (MMC) had passed the first recording site. Intravenous infusion of NPY (50–100 pmol kg −1 min −1 ) did not affect the MMC in the duodenum but interrupted its distal propagation and inhibited spiking in the jejunum. At higher doses, NPY (200–800 pmol kg −1 min −1 ) abolished the MMC at all recording sites. Effects of NPY on myoelectric activity were not prevented by guanethidine, phentolamine, propranolol, or naloxone. The effects of NPY on myoelectric activity corresponded to a dose‐related slowing of transit of the marker. In controls, the peak of the marker was propagated ahead of the activity front over the three recording sites. NPY (100 pmol kg −1 min −1 ) slowed transit, with the peak of the marker proximal to the third electrode site. NPY (400 pmol kg −1 min −1 ) further delayed transit, with the peak of the marker proximal to the second electrode site. We conclude that the activity front of the MMC exerts a high propulsive capacity. NPY produced a dose‐related nonadrenergic inhibition of the intestinal myoelectric activity, which may account for a delayed transit of intestinal contents.