Cholecystokinin-induced persistent stimulation of enzyme secretion from pancreatic acini

Abstract

When guinea pig pancreatic acini are first incubated with cholecystokinin [CCK], washed to remove free CCK and then reincubated in fresh incubation solution, there is significant residual stimulation of amylase secretion. This residual stimulation requires relatively high concentrations of the secretagog, is reversible, and is specific for CCK. Induction of residual stimulation occurs more rapidly at 37.degree. C (maximal by 1 min) than at 4.degree. C (maximal by 10 min), and once induced, residual stimulation persists for up to 75 min at 37.degree. C and for > 90 min at 4.degree. C. The persistent effect of CCK on enzyme secretion cannot be accounted for by incomplete removal of the secretagog by the wash procedure or by activation of some intermediate step in the mechanism of action of CCK that persists after the secretagog dissociates from its receptors. Instead, CCK-induced residual stimulation of enzyme secretion appears to result from persistent occupation of CCK receptors by the secretagog.