HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 287/6/G1109    most recent 00080.2004v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by Grider, J. R. Search for Related Content PubMed PubMed Citation Articles by Grider, J. R.

NEUROREGULATION AND MOTILITY

Gastrin-releasing peptide is a modulatory neurotransmitter of the descending phase of the peristaltic reflex

Departments of Physiology and Medicine, Medical College of Virginia, Virginia Commonwealth University, Richmond, Virginia 23298

Submitted 19 February 2004 ; accepted in final form 28 July 2004

The physiological role of gastrin-releasing peptide (GRP) and of its cognate receptors in regulating the intestinal peristaltic reflex was examined in a three-compartment flat-sheet preparation of rat colon. Mucosal stimulation applied to the central compartment at high, but not low levels of intensity, induced GRP release in the caudad compartment where descending relaxation was measured, but not into the ascending compartment where ascending contraction was measured or into the central compartment where the stimuli were applied. The selective GRP (BB₂) receptor antagonist, [D-Phe⁶,des-Met¹⁴]bombesin_6–14, inhibited descending relaxation and VIP release in the caudad compartment induced by high but not by low levels of stimulation applied to the mucosa in the central compartment. The selective neuromedin B (BB₁) receptor antagonist, BIM-23127, had no effect on descending relaxation or VIP release. Neither the BB₁ nor the BB₂ antagonist had any effect on ascending contraction or substance P release in the orad compartment. Consistent with the effects of the antagonists on the peristaltic reflex, the BB₂ antagonist but not the BB₁ antagonist decreased the velocity of propulsion of artificial fecal pellets through isolated segments of guinea pig distal colon. The results indicate that GRP is selectively released from myenteric neurons in descending pathways during the peristaltic reflex and that it acts via BB₂ receptors to augment the descending phase of the peristaltic reflex and propulsion.

enteric nervous system; vasoactive intestinal peptide; neuromedin B; colon

This article has been cited by other articles:

				Q. Gu and L.-Y. Lee Sensitization of pulmonary chemosensitive neurons by bombesin-like peptides in rats Am J Physiol Lung Cell Mol Physiol, December 1, 2005; 289(6): L1104 - L1112. [Abstract] [Full Text] [PDF]