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Medizin - Open Access LMU - Teil 02/22Language: de Genres: Education, Health & Fitness, Medicine Contact email: Get it Feed URL: Get it iTunes ID: Get it |
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Evidence that substance P does not mediate slow synaptic excitation within the myenteric plexus
Monday, 1 January, 1979
ELECTRICAL stimulation of presynaptic fibres to the so-called AH1 or type II2 myenteric neurones in guinea pig small intestine evokes a slow excitatory postsynaptic potential (e.p.s.p.) characterised by long-lasting depolarisation associated with increased membrane resistance and augmented excitability3. Two substances have been implicated as possible neurotrans-mitters for the slow e.p.s.p. Katayama and North reported that application of substance P to myenteric neurones mimicked the slow e.p.s.p.4, and J.D.W. and C.J.M. presented several lines of evidence for serotonin as the transmitter substance5,6. We now report that methysergide, a drug which abolishes both the slow e.p.s.p. and the action of exogenous serotonin5,6, does not affect the action of substance P on guinea pig myenteric neurones. The results suggest that substance P is unlikely to be the neuro-transmitter which mediates the slow e.p.s.p.
