Central cholecystokinin activity in irritable bowel syndrome, panic disorder, and healthy controls.
OBJECTIVE
Irritable bowel syndrome (IBS) and panic disorder (PD) coexist with a high frequency. However, the nature of this relationship remains obscure. We have proposed that PD and IBS may share a common dysfunction of the central cholecystokinin (CCK) system. To test this hypothesis, we assessed whether the enhanced panicogenic response to CCK-tetrapeptide (CCK-4) observed in PD is also present in IBS.


METHODS
Eight psychiatrically healthy IBS patients, 8 PD patients with no history of IBS, and 12 normal controls received a bolus injection of CCK-4 and placebo on two separate days in a double-blind, randomized fashion.


RESULTS
Consistent with previous findings, panicogenic sensitivity to CCK-4 was enhanced in PD patients relative to controls. In contrast, IBS patients exhibited a response that was comparable to controls. Interestingly, CCK-4-induced nausea and abdominal distress were decreased in IBS patients relative to the other groups. No diagnostic difference was noted for cardiovascular response to CCK-4.


CONCLUSIONS
These data indicate that IBS patients with no lifetime psychiatric history do not share the CCK-2 receptor dysfunction implicated in the pathophysiology of PD and that this dysfunction may not be a common mechanism for both CNS and enteric nervous system disorders. Nevertheless, the results suggest that a dysfunction of the CCK system may be involved in the pathophysiology of some enteric symptoms associated with IBS.
Koszycki
Diana
D
Department of Psychiatry, University of Ottawa, and the University of Ottawa Institute of Mental Health Research, Royal Ottawa Hospital, Ottawa, Ontario, Canada. dkoszyck@rohcg.on.ca
Torres
Stéphane
S
Swain
James E
JE
Bradwejn
Jacques
J
D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D004311:Double-Blind Method; D005260:Female; D005765:Gastrointestinal Agents / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D016584:Panic Disorder / Q000503:physiopathology*; D043887:Receptor, Cholecystokinin B / Q000819:agonists*; D013758:Tetragastrin / Q000494:pharmacology*
D005765:Gastrointestinal Agents; D043887:Receptor, Cholecystokinin B; D013758:Tetragastrin