ROLE OF CHOLECYSTOKININ IN REGULATION OF GASTROINTESTINAL MOTOR FUNCTIONS

By means of loxiglumide, a potent and highly specific antagonist for cholecystokinin (CCK), the effects of blocking CCK receptors on gastrointestinal motility were investigated in a placebo-controlled study in healthy young men (aged 21-39, mean 24 years). Gallbladder contraction stimulated by ingestion of a liquid test meal was completely abolished by oral administration of loxiglumide 30 min before the test meal. Gastric emptying of radio-opaque markers ingested with the test meal was significantly accelerated by loxiglumide (area under the curve [markers × h] 33·3 [SEM 3·8] vs 17·9 [2·7] after placebo). No effect of loxiglumide was found on small-bowel transit time, but 7 days' treatment with oral loxiglumide (800 mg three times daily) significantly shortened colonic transit time (29·4 [4·1] h after placebo, 15·0 [3·4] h after loxiglumide). It is concluded that CCK is an important mediator of meal-induced gallbladder contraction and is involved in the regulation of gastrointestinal motility in man.