PKA inhibitors do not markedly affect the potentiation of glucose-induced insulin release by GLP-1. PKA inhibitors do not markedly affect the potentiation of glucose-induced insulin release by GLP-1. Insulin secretion from isolated islets was determined as described in Fig. 1. Islets were incubated with or without 10 nmol/l GLP-1. H-89 and KT5720 were used at 5 μmol/l, Rp-cAMP (Rp-c) was used at 100 μmol/l, and nifedipine (Nif) was used at 1 μmol/l. The data are the means ± SD from four independent experiments. Mitsuhiro Nakazaki et al. Diabetes 2002;51:3440-3449 ©2002 by American Diabetes Association