I Synnerstad1, E Ekblad, F Sundler, L Holm. 1. Department of Physiology and Medical Biophysics, Biomedical Center, Uppsala University, Sweden.
Abstract
BACKGROUND & AIMS: Oscillating (3-7 cycles/min) high pressures in gastric glands during acid secretion suggest the existence of rhythmically contracting mucosal muscles. The aim of this study was to study vasoactive intestinal peptide (VIP), an inhibitory neurotransmitter in the gastrointestinal tract, in relation to mucosal muscles, glandular pressure, and blood flow. METHODS: Rat, dog, and human mucosae were examined immunocytochemically for smooth muscle actin and VIP. Glandular pressure was measured using microelectrodes, red blood cell velocity (V[RBC]) was measured using a cross-correlation technique, and blood flow was measured using laser Doppler flowmetry in exposed gastric mucosa of thiobutabarbital sodium-anesthetized rats. RESULTS: Actin immunostaining showed muscle strands arising from muscularis mucosae, extending toward the gastric pits. VIP-immunoreactive nerve fibers were found in close relation to these muscles. VIP, administered intra-arterially close to the stomach (2 microg/kg bolus, followed by 10 microg x kg[-1] x h[-1]), significantly decreased glandular pressure from 18.2 +/- 1.6 to 8.9 +/- 1.6 mm Hg and almost eliminated the pressure oscillations. VIP infusion also abolished the oscillations in V(RBC) and significantly increased blood flow by approximately 35%. CONCLUSIONS: Contracting mucosal muscles may be responsible for oscillations in glandular pressure and possibly also in V(RBC). VIP probably relaxes these muscles.
BACKGROUND & AIMS: Oscillating (3-7 cycles/min) high pressures in gastric glands during acid secretion suggest the existence of rhythmically contracting mucosal muscles. The aim of this study was to study vasoactive intestinal peptide (VIP), an inhibitory neurotransmitter in the gastrointestinal tract, in relation to mucosal muscles, glandular pressure, and blood flow. METHODS:Rat, dog, and human mucosae were examined immunocytochemically for smooth muscle actin and VIP. Glandular pressure was measured using microelectrodes, red blood cell velocity (V[RBC]) was measured using a cross-correlation technique, and blood flow was measured using laser Doppler flowmetry in exposed gastric mucosa of thiobutabarbital sodium-anesthetized rats. RESULTS: Actin immunostaining showed muscle strands arising from muscularis mucosae, extending toward the gastric pits. VIP-immunoreactive nerve fibers were found in close relation to these muscles. VIP, administered intra-arterially close to the stomach (2 microg/kg bolus, followed by 10 microg x kg[-1] x h[-1]), significantly decreased glandular pressure from 18.2 +/- 1.6 to 8.9 +/- 1.6 mm Hg and almost eliminated the pressure oscillations. VIP infusion also abolished the oscillations in V(RBC) and significantly increased blood flow by approximately 35%. CONCLUSIONS: Contracting mucosal muscles may be responsible for oscillations in glandular pressure and possibly also in V(RBC). VIP probably relaxes these muscles.
Authors: Thomas J Heppner; Jeffrey J Layne; Jessica M Pearson; Hagop Sarkissian; Mark T Nelson Journal: Am J Physiol Regul Integr Comp Physiol Date: 2011-06-01 Impact factor: 3.619
Authors: Hyo-Yung Yun; Rohyun Sung; Young Chul Kim; Woong Choi; Hun Sik Kim; Heon Kim; Gwang Ju Lee; Ra Young You; Seon-Mee Park; Sei Jin Yun; Mi-Jung Kim; Won Seop Kim; Young-Jin Song; Wen-Xie Xu; Sang Jin Lee Journal: Korean J Physiol Pharmacol Date: 2010-10-31 Impact factor: 2.016