Kinetics of amylase release by dispersed acini prepared from guinea pig pancreas

When incubated with a secretagogue such as cholecystokinin (CCK), dispersed acini prepared from guinea pig pancreas released substantially more amylase than did dispersed single acinar cells. With CCK the rate of amylase release from dispersed acini decreased after 5 min of incubation and remained constant for the subsequent 25 min. The magnitude of the reduction in the rate of amylase release after 5 min was greater with higher concentrations of CCK. With vasoactive intestinal peptide (VIP), the rate of amylase release remained constant for at least 30 min. With CCK plus VIP, potentiation of the rate of amylase release occurred only during the first 15 min of incubation. After 15 min of incubation, the effects of the two peptides were additive. When dispersed acini were first incubated with CCK, potentiation of amylase release occurred only when VIP was added during the initial 10 min of incubation. In contrast, when cells were first incubated with VIP, potentiation of amylase release occurred when CCK was added as long as 30 min after VIP.