Serotonin and cholecystokinin activate different populations of rat mesenteric vagal afferents.
This electrophysiological study was performed to elucidate the interactions of serotonin (5-hydroxytryptamine, 5-HT) and cholecystokinin (CCK) on mesenteric afferents supplying the rat jejunum. 5-HT and CCK produced characteristic responses in multi-unit recordings of mesenteric afferents. Waveform analysis to extract single units from the whole nerve recording identified populations of single afferents that were sensitive to either 5-HT or CCK, but not both. Furthermore, devazepide (0.5 mg/kg) completely abolished the response to CCK without altering the response to 5-HT while granisetron (0.5 mg/kg) abolished the response to 5-HT with no effect on the response to CCK. These results suggest that there are discrete, noninteractive populations of jejunal afferents that possess either 5-HT3 or CCK-A receptors but not both.
Hillsley
K
K
Department of Biomedical Science, University of Sheffield, Western Bank, UK.
Grundy
D
D
D000818:Animals; D002766:Cholecystokinin / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D020109:Devazepide / Q000494:pharmacology; D004594:Electrophysiology; D017829:Granisetron / Q000494:pharmacology; D006727:Hormone Antagonists / Q000494:pharmacology; D007583:Jejunum / Q000294:innervation*; D008297:Male; D009475:Neurons, Afferent / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000494:pharmacology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D014630:Vagus Nerve / Q000166:cytology / Q000187:drug effects*
D002766:Cholecystokinin; D020109:Devazepide; D017829:Granisetron; D006727:Hormone Antagonists; D012701:Serotonin; D012702:Serotonin Antagonists