INS and type 1 diabetes mellitus: However, we found a significant decrease in the depolarization speed in T1DM GPs treated with insulin (6.2 ± 0.56 μm/s) or in cardiac myocytes isolated from this group that were preincubated with either 0.4 mM Palm (4.6 ± 0.57 μm/s) or 4 mM GSHee (3.2 ± 0.48 μm/s) in the presence of 10 mM glucose.