Figure 4

Effect of ARA290 on insulin secretion pathway in GK rat islets. (A) Insulin secretion (µU/islet/h) was assessed in batches of three islets incubated in 3.3 mmol/L G without ARA290 (□) or with 10 ng/mL ARA290 (■) and supplemented with 0.25 mmol/L diazoxide or 30 mmol/L KCl as indicated in the graph. (B) Insulin secretion (µU/islet/h) was assessed in batches of three islets incubated in 16.7 mmol/L G without ARA290 (□) or with 10 ng/mL ARA290 (■) and supplemented with 0.25 mmol/L diazoxide or 30 mmol/L KCl as indicated in the graph. Results represent means ± SEM of n = 7 experiments. ^φP < 0.02 versus 16.7 mmol/L G control, *P < 0.02 versus 16.7 mmol/L G control, ^ξP < 0.02 versus ARA290, ^##P < 0.01 versus diazoxide + KCl, ns indicates no statistical difference. (C) Insulin secretion (µU/islet/h) was assessed in batches of three islets incubated for 1 h with 3.3 mmol/L G (□) or 16.7 mmol/L G (■) and supplemented with 10 ng/mL ARA290 or PKA inhibitor H89 (10 µmol/L). Results represent means ± SEM of n = 5 experiments. **P < 0.01 versus 16.7 mmol/L G, ^##P < 0.01 versus ARA290. (D) Insulin secretion (µU/islet/h) was assessed in batches of three islets incubated for 1 h with 3.3 mmol/L G (□) or 16.7 mmol/L G (■) and supplemented with 10 ng/mL ARA290 or nimodipine (5 µmol/L). Results represent means ± SEM of n = 4 experiments. *P < 0.05 versus 16.7 mmol/L G, ^###P < 0.001 versus ARA290.