Dependence of cholecystokinin-8-stimulated insulin release on high glucose levels is evidenced by pseudo-alpha-D-glucose in rat pancreas and islets.

The glucose-dependency of cholecystokinin-8 (CCK-8)-stimulated insulin release was investigated at high (11.1 and 16.7 mM) glucose concentrations in rat pancreas perfusion and islet perifusion using glucose analogues, pseudo-alpha-D-glucose and 2-deoxy-D-glucose. In perfused pancreas, both glucose analogues (22.4 mM) inhibited high glucose (16.7 mM)-induced insulin release, but not normal glucose (5.6 mM)-induced insulin release, with or without CCK-8 (1 nM). In perifused islets, the same level of either of the glucose analogues inhibited high glucose (11.1 mM)-induced insulin release, with or without CCK-8 (100 nM). These results demonstrate that CCK-8-stimulated insulin release only at high glucose level is glucose-dependent.