Fig 6. Effects of JNK inhibition on InR1G glucagon secretion.

(A) Cells were cultured with DMSO or 10 μM SP600125 for 1 h, and stimulated using H₂O₂ (100 μM) for 15 min, and pJNK and JNK levels were determined. (B) JNK and pJNK levels in cells treated with regular (11.1 mM) or high (25 mM) glucose concentrations for 12 h, with the addition of DMSO or 10 μM SP600125. Relative pJNK expressions were determined by densitometry, and they were normalized using total JNK levels. (C) Glucagon secretion in cells treated with regular (11.1 mM, white) or high (25 mM, black) glucose concentrations, together with DMSO or 10 μM SP600125 for 12 h before the static incubation with the indicated glucose levels. (D) Cells were treated with DMSO or 10 μM SP600125, for 12 h before the static incubation with 7 mM glucose with (hatched)/without the addition of 10 mM L-Arg. Representative graphs/images selected from the results of 3 or 4 independent experiments are shown. n = 3–4 in each group; data are expressed as mean ± SEM; *P<0.05, between the indicated groups.