Publication:
ATP and 5-HT are principal neurotransmitters in the descending excitatory reflex pathway of the guinea-pig ileum

dc.contributor.author Monro, R. L. en_US
dc.contributor.author Bertrand, P. P en_US
dc.contributor.author Bornstein, J. C. en_US
dc.date.accessioned 2021-11-25T13:35:02Z
dc.date.available 2021-11-25T13:35:02Z
dc.date.issued 2002 en_US
dc.description.abstract Neurotransmission underlying descending excitatory reflexes evoked by distension was studied in opened segments of guinea-pig ileum and compared with peristalsis in intact segments. The opened segments were distended by inflating a balloon against the serosa at the oral end and changes in muscle length recorded from the anal end. Distension elicited contractions in both circular (CM) and longitudinal (LM) muscle layers. Granisetron, a 5-HT3receptor antagonist (10 nmol L−1to 1 µmol L−1) reduced CM contractions (24% control), without affecting the LM. The P2 receptor antagonist, pyridoxal phosphate-6-azopheyl-2',4'-disulphonic acid (PPADS; 10 µmol L−1), reduced CM contractions to 31% and LM contractions to 39%. Hexamethonium (500 µmol L−1) enhanced LM contractions, but had no effect on CM contractions. Granisetron (1 µmol L−1) had no significant effect on the threshold for peristaltic contractions in a modified Trendelenburg preparation, but decreased the decay time of these contractions by 37%. PPADS (10 µmol L−1) had no significant effect in this preparation. Thus, the descending excitatory pathways to CM and LM can be distinguished pharmacologically; the former depend on 5-HT3and P2 ATP receptors, the latter are independent of 5-HT3receptors. Nicotinic receptors may have little part in either pathway. These properties differ from conventional peristaltic reflexes, which are effectively abolished by nicotinic blockade. en_US
dc.identifier.issn 1365-2982 en_US
dc.identifier.uri http://hdl.handle.net/1959.4/40033
dc.language English
dc.language.iso EN en_US
dc.rights CC BY-NC-ND 3.0 en_US
dc.rights.uri https://creativecommons.org/licenses/by-nc-nd/3.0/au/ en_US
dc.source Legacy MARC en_US
dc.title ATP and 5-HT are principal neurotransmitters in the descending excitatory reflex pathway of the guinea-pig ileum en_US
dc.type Journal Article en
dcterms.accessRights metadata only access
dspace.entity.type Publication en_US
unsw.accessRights.uri http://purl.org/coar/access_right/c_14cb
unsw.identifier.doiPublisher http://dx.doi.org/10.1046/j.1365-2982.2002.00325.x en_US
unsw.relation.faculty Medicine & Health
unsw.relation.ispartofjournal Neurogastroenterology & Motility en_US
unsw.relation.ispartofpagefrompageto 255-264 en_US
unsw.relation.ispartofvolume 14 en_US
unsw.relation.originalPublicationAffiliation Monro, R. L. en_US
unsw.relation.originalPublicationAffiliation Bertrand, P. P, Medical Sciences, Faculty of Medicine, UNSW en_US
unsw.relation.originalPublicationAffiliation Bornstein, J. C. en_US
unsw.relation.school School of Medical Sciences *
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