AGI Mar 39/3

Coffin, Benoit, Sophie Fossati, Bernard Flourié, Marc Lémann, Pauline Jouet, Claire Franchisseur, Raymond Jian, and Jean-Claude Rambaud. Regional effects of cholecystokinin octapeptide on colonic phasic and tonic motility in healthy humans. Am. J. Physiol. 276 (Gastrointest. Liver Physiol. 39): G767–G772, 1999.—The aim of this study was to assess in nine healthy subjects the effects of CCK octapeptide (CCK-8) on colonic tonic activity, measured by a barostat, and phasic activity, measured by manometry. On 2 consecutive days, recordings were performed in the unprepared proximal and distal colons during intravenous infusion of saline and CCK-8 at 5, 20, and 40 ng·kg21 ·h21. In the proximal colon CCK-8 induced, at the 20 and 40 ng·kg21 ·h21 doses, a tonic relaxation with an increase in barostat bag volume to 156 6 25 and 157 6 19% of basal (P , 0.01) and a decrease in phasic activity to 72 6 7 and 76 6 7% of basal (P , 0.01). In the distal colon, CCK-8 induced, at the 20 and 40 ng·kg21 ·h21 doses, a tonic relaxation (increase in intrabag volume to 133 6 12 and 149 6 15%, respectively; P , 0.01), whereas phasic activity increased (128 6 8 and 132 6 6%, respectively; P , 0.01). Effects of CCK-8 on tonic and phasic activities are different according to the colonic segment. Because meals induce colonic tonic contraction, our results suggest that CCK, as a hormone, is not an important mediator of the response of the colon to feeding in humans.