Culturing of HRTCs with 1 nM of C-peptide resulted in increase in PKCε phosphorylation, while phosphorylation of PKCs α/β increased by high glucose concentrations.

Cells were cultured as described in “Materials and Methods”. Total cell lysates were subject to Western blot analysis to determine PKCs phosphorylation. A representative Western blot image is shown in the upper panel of each graph. A. Phospho PKCα/β. B. Phospho PKCδ, C. Phospho PKCε. GAPDH protein was used as a loading control. Results are means ± SE for 6 independent experiments. * P<0.05 versus 5 mM glucose without C-peptide.