Size distribution histograms of myelinated fibers. (A), respective axons (B) and g ratio (C) of sural nerve in normotensive Wistar rat (WR), normotensive Wistar rat with chronically induced diabetes (WR + STZ), Spontaneously hypertensive rat (SHR) and Spontaneously hypertensive rat with chronically induced diabetes (SHR + STZ). WR + STZ showed a higher peak at larger fibers while the SHR + STZ showed a lower peak of these fibers compared to all other groups. Myelinated axons presented a slight shift to smaller size in SHR + STZ group compared to all others. The g ratio distributions in both SHR groups are shifted to the right compared to normotensive groups.