Central 5-hydroxytryptaminergic function in irritable bowel syndrome.
BACKGROUND
Psychological factors may contribute to the aetiology and exacerbation of symptoms in irritable bowel syndrome (IBS), suggesting that the central nervous system may be an important site of dysfunction in IBS. Hormonal responses after a serotonergic challenge assess the functional integrity of central 5-hydroxytryptaminergic pathways and are diminished in depression. The aim of this study was to determine whether hormonal responses in IBS after a serotonergic challenge would be decreased, as in depression, or exaggerated, as have been reported in another functional gastrointestinal disorder, nonulcer dyspepsia.


METHODS
Fourteen IBS patients, 16 healthy volunteers, and 9 patients with inflammatory bowel disease were given 30 mg d-fenfluramine, a selective stimulus to central 5-hydroxytryptaminergic pathways.


RESULTS
Plasma prolactin and cortisol concentrations during the following 5 h increased to a similar extent in all three subject groups, despite increased levels of anxiety and depression (as scored on the Hospital Anxiety and Depression Scale and Beck Depression Inventory) in the IBS and inflammatory bowel disease patients compared with the healthy controls. Base-line cortisol concentration correlated with the magnitude of affective disorder.


CONCLUSIONS
In contrast to the alterations of central 5-hydroxytryptamine receptor sensitivity seen in depression and non-ulcer dyspepsia, central 5-hydroxytryptaminergic pathways function normally in IBS.
Gorard
D A
DA
Dept. of Gastroenterology, St. Bartholomew's Hospital, West Smithfield, London, UK.
Dewsnap
P A
PA
Medbak
S H
SH
Perry
L A
LA
Libby
G W
GW
Farthing
M J
MJ
D000328:Adult; D001007:Anxiety / Q000139:chemically induced; D002490:Central Nervous System / Q000378:metabolism / Q000503:physiopathology*; D003109:Colonic Diseases, Functional / Q000378:metabolism / Q000503:physiopathology*; D003863:Depression / Q000139:chemically induced; D005260:Female; D005277:Fenfluramine / Q000009:adverse effects / Q000494:pharmacology; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D015212:Inflammatory Bowel Diseases / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011388:Prolactin / Q000097:blood; D012701:Serotonin / Q000378:metabolism*; D018490:Serotonin Agents / Q000009:adverse effects / Q000494:pharmacology
D018490:Serotonin Agents; D005277:Fenfluramine; D012701:Serotonin; D011388:Prolactin; D006854:Hydrocortisone