The axon area of the myelinated nerve was increased in 17-week-old healthy mice (n = 6) compared with 8-week-old healthy mice (n = 5). In 17-week-old diabetic mice (n = 5), the axon area was larger than that in 8-week-old healthy mice, but smaller than that in 17-week-old healthy mice. Maximum and minimum axon diameter showed similar trends to those for axon area. There Inhibitors,research,lifescience,medical were no significant differences in axon density or axon number between groups of mice. Myelin area in 17-week-old healthy mice was significantly larger than that in 8-week-old healthy and

17-week-old diabetic mice. There was no significant difference in myelin area between 8-week-old healthy and 17-week-old diabetic mice. Table 1 Morphometric data on myelinated fibers of sciatic nerves The axon size distribution of myelinated fibers was examined in each group of mice (Fig. 5). The population of large myelinated axons with a cross-sectional area >40 μm2 was significantly increased in 17-week-old healthy and diabetic mice compared with that

in 8-week-old healthy mice. The population of small myelinated axons Inhibitors,research,lifescience,medical with a cross-sectional area ≤20 μm2 was significantly reduced in 17-week-old healthy and diabetic mice compared with that in 8-week-old healthy mice, being more reduced in 17-week-old healthy mice than in 17-week-old diabetic mice. Figure Inhibitors,research,lifescience,medical 5 Axon size distribution of myelinated fibers in the sciatic nerves. Eight-week-old healthy mice (H8) (open bars; n = 6), 17-week-old healthy mice (H17) (stippled bars; n = 5), 17-week-old diabetic mice (DM17) (shaded bars; n = 5). H17, DM17 versus H8: … chemical structure unmyelinated nerve fibers Unmyelinated fibers of sciatic nerve in each group of mice were also examined under an electron microscope (Table Inhibitors,research,lifescience,medical 2). The axon area of unmyelinated fibers was significantly reduced in 17-week-old diabetic mice (n = 5) compared with 8-week-old Inhibitors,research,lifescience,medical healthy (n = 5) and 17-week-old healthy (n = 5) mice. There was no significant difference in axon area between 8-week-old and 17-week-old healthy mice, although a slight increase was observed in 17-week-old healthy mice. There was no significant difference in the maximum diameter in each group. The measurements before of minimum

axon diameters showed similar trends to those for axon area. There were no significant differences in axon density or number between groups of mice. Table 2 Morphometric data on unmyelinated fibers of sciatic nerves The axon size distribution of unmyelinated fibers was examined in each group of mice (Fig. 6). The population of small unmyelinated axons with a cross-sectional area ≤0.3 μm2 was significantly increased in 17-week-old diabetic mice compared with that in 8-week-old and 17-week-old healthy mice, while the population of large unmyelinated axons with a cross-sectional area >0.7 μm2 was significantly reduced in 17-week-old diabetic mice compared with the other groups of mice. Figure 6 Axon size distribution of unmyelinated fibers in the sciatic nerves.