Inter-digestive and post-prandial antro-pyloro-duodenal motor activity in humans: effect of 5-hydroxytryptamine 1 receptor agonism.
BACKGROUND
Little is known about the effect of 5-hydroxytryptamine 1 (5-HT(1)) receptor agonism on the co-ordinated motor activity of the gastric antrum, pylorus and duodenum under fasting and fed conditions.


OBJECTIVE
To evaluate the effect of sumatriptan, a 5-HT(1) agonist, on fasting and fed antro-pyloro-duodenal motility.


METHODS
In study 1, antro-pyloro-duodenal motility was recorded for two phase IIIs of the migrating motor complex and then, following either a subcutaneous injection of sumatriptan 6 mg or saline control, for at least one additional phase III in 11 healthy volunteers (21-36 years). In study 2, the post-prandial motility was recorded for 3 h after either a subcutaneous injection of sumatriptan 6 mg or saline control in 10 healthy volunteers (18-36 years).


RESULTS
Sumatriptan prolonged the migrating motor complex cycle (P = 0.009) by increasing the duration of phase II (P = 0.02) but not phases I and III. Post-prandially, sumatriptan reduced the activity index (P = 0.017) by reducing the frequency of co-ordinated motor activity involving the antrum and/or the duodenum (P < 0.05).


CONCLUSIONS
5-HT(1) receptor agonism increases the periodicity of the migrating motor complex and reduces the occurrence of post-prandial co-ordinated motor activity involving the gastric antrum, pylorus and duodenum.
Calvert
E L
EL
Academic Department of Medicine, University Hospital of South Manchester, Manchester, UK.
Whorwell
P J
PJ
Houghton
L A
LA
D000293:Adolescent; D000328:Adult; D004063:Digestion / Q000502:physiology*; D004386:Duodenum / Q000294:innervation* / Q000502:physiology; D005215:Fasting / Q000502:physiology; D005260:Female; D005769:Gastrointestinal Motility / Q000187:drug effects*; D006801:Humans; D008297:Male; D008365:Manometry; D009046:Motor Neurons / Q000187:drug effects* / Q000502:physiology; D019518:Postprandial Period / Q000502:physiology*; D011708:Pylorus / Q000294:innervation; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*; D018170:Sumatriptan / Q000494:pharmacology*
D017366:Serotonin Receptor Agonists; D018170:Sumatriptan