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Effects of hydrogen sulphide on motility patterns in the rat colon
Author(s) -
Gil V,
Parsons SP,
Gallego D,
Huizinga JD,
Jimenez M
Publication year - 2013
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/bph.12100
Subject(s) - motility , interstitial cell of cajal , carbachol , cholinergic , myenteric plexus , excitatory postsynaptic potential , inhibitory postsynaptic potential , chemistry , neuroscience , endocrinology , medicine , biology , microbiology and biotechnology , biochemistry , smooth muscle , receptor , immunohistochemistry
Background and Purpose Hydrogen sulphide ( H 2 S ) is an endogenous gaseous signalling molecule with putative functions in gastrointestinal motility regulation. Characterization of H 2 S effects on colonic motility is crucial to establish its potential use as therapeutic agent in the treatment of colonic disorders. Experimental Approach H 2 S effects on colonic motility were characterized using video recordings and construction of spatio‐temporal maps. Microelectrode and muscle bath studies were performed to investigate the mechanisms underlying H 2 S effects. NaHS was used as the source of H 2 S . Key Results Rhythmic propulsive motor complexes ( RPMCs ) and ripples were observed in colonic spatio‐temporal maps. Serosal addition of NaHS concentration‐dependently inhibited RPMCs . In contrast, NaHS increased amplitude of the ripples without changing their frequency. Therefore, ripples became the predominant motor pattern. Neuronal blockade with lidocaine inhibited RPMCs , which were restored after administration of carbachol. Subsequent addition of NaHS inhibited RPMCs . Luminal addition of NaHS did not modify motility patterns. NaHS inhibited cholinergic excitatory junction potentials, carbachol‐induced contractions and hyperpolarized smooth muscle cells, but did not modify slow wave activity. Conclusions and Implications H 2 S modulated colonic motility inhibiting propulsive contractile activity and enhancing the amplitude of ripples, promoting mixing. Muscle hyperpolarization and inhibition of neurally mediated cholinergic responses contributed to the inhibitory effect on propulsive activity. H 2 S effects were not related to changes in the frequency of slow wave activity originating in the network of interstitial cells of Cajal located near the submuscular plexus. Luminal H 2 S did not modify colonic motility probably because of epithelial detoxification.