GS inhibits insulin synthesis and secretion in INS-1 cells.

<p>INS-1 cells were treated with NG, 1% GS, 2% GS, 5% GS or 10% GS for 1, 3, 6 and 12 h, and then <i>Ins1</i> (A) and <i>Ins2</i> (B) gene expression levels were analyzed by real-time RT-PCR. After treatment of INS-1 cells with the indicated concentration of GS for 24 h, the KSIS assay (C) was carried out, and the potassium-stimulated insulin secretion index (KSI) (D) and total insulin in the cellular extract (E) were determined. The insulin level was determined by RIA. Insulin secretion and content were normalized by the total protein concentration. Values are the mean ± SEM of three individual experiments. *<i>P</i><0.05 vs. NG; **<i>P</i><0.01 vs. NG.