Abstract
To examine the effect of atropine on cholecystokinin (CCK) release, we studied CCK concentrations after a liquid fat meal in five volunteers both with and without pretreatment with atropine. In control studies peak plasma CCK 8 concentrations were 15.0 ± 6.2 pmol l-1, and the integrated plasma CCK 8 response was 415 ± 216 pmol l-1 2 h-1. Peak plasma CCK 33/39 concentrations were 16.5 ± 4.6 pmol l-1, and integrated CCK 33/9 response was 469 ± 200 pmol l-1 2h-1. After pretreatment with atropine postprandial CCKs were undetectable (p < 0.05 versus control studies). The abolition of measurable CCK release by atropine may entirely account for its inhibitory effects on biliary secretion and in part for its effect on the pancreas.