Propagation of slow waves in the guinea-pig gastric antrum
Intracellular recordings were made from the circular layer of the intact muscular wall of the guinea-pig gastric antrum in preparations where much of the corpus remained attached. When two electrodes were positioned parallel to and near to the greater curvature, slow waves were first detected at the...
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Published in | The Journal of physiology Vol. 571; no. 1; pp. 165 - 177 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
9600 Garsington Road , Oxford , OX4 2DQ , UK
The Physiological Society
15.02.2006
Blackwell Science Ltd Blackwell Science Inc |
Subjects | |
Online Access | Get full text |
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Summary: | Intracellular recordings were made from the circular layer of the intact muscular wall of the guinea-pig gastric antrum in
preparations where much of the corpus remained attached. When two electrodes were positioned parallel to and near to the greater
curvature, slow waves were first detected at the oral site and subsequently at the anal site: the oro-anal conduction velocity
was found to be 2.5 mm s â1 . When one electrode was positioned near the greater curvature and the other at a circumferential location, slow waves were
first detected near the greater curvature and subsequently at the circumferential site: the circumferential conduction velocity
was 13.9 mm s â1 . When recordings were made from preparations in which the circular muscle layer had been removed, the oro-anal and the circumferential
conduction velocities were both about 3.5 mm s â1 . When slow waves were recorded from preparations in which much of the myenteric network of antral interstitial cells (ICC MY ) had been dissected away, slow waves were first detected near the region of intact ICC MY and subsequently at a circumferential location: the circumferential conduction velocity of slow waves in regions devoid of
ICC MY was 14.7 mm s â1 . When the electrical properties of isolated single bundles of circular muscle were determined, their length constants were
about 3 mm and their time constant about 230 ms, giving an asymptotic electrotonic propagation velocity of 25 mm s â1 . Oro-anal electrical coupling between adjacent bundles of circular muscle was found to vary widely: some bundles were well
connected to neighbouring bundles whereas others were not. Together the observations suggest that the slow oro-anal progression
of slow waves results from a slow conduction velocity of pacemaker potentials in the myenteric network of interstitial cells.
The rapid circumferential conduction of slow waves results from the electrical properties of the circular muscle layer which
allow intramuscular ICC (ICC IM ) to support the radial spread of slow waves: regions of high resistance between bundles prevent the anally directed spread
of slow waves within the circular layer. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0022-3751 1469-7793 |
DOI: | 10.1113/jphysiol.2005.100735 |