Results of histomorphometry and electron microscopy and immunohistochemistry (mean ± SEM)
| 4 Weeks | 8 Weeks | |
|---|---|---|
| Myelin thickness (μm)a | ||
| NGF | 0.43 ± 0.09 | |
| EPO | 0.57 ± 0.08, P < .05 | |
| Axon diameter (μm)a | ||
| NGF | 1.73 ± 0.51 | |
| EPO | 2.39 ± 0.32, P < .05 | |
| Myelinated axon counts (at original magnification ×400)b | ||
| NGF | 17.56 ± 4.19 | 49.30 ± 9.56 |
| EPO | 22.90 ± 5.24, P < .05 | 58.00 ± 7.73, P < .05 |
| MOD (at original magnification ×400)b | ||
| NGF | 0.2173 ± 0.0257 | 0.3089 ± 0.0343 |
| EPO | 0.2419 ± 0.0204, P < .05 | 0.3611 ± 0.0547, P < .05 |
| IOD (at original magnification ×400)b | ||
| NGF | 15.8494 ± 3.0825 | 16.6742 ± 1.7156 |
| EPO | 19.4382 ± 4.1861, P < .05 | 22.4111 ± 4.3418, P < .01 |
a At 8 weeks after surgery, nerves treated with EPO had significantly larger myelin thickness and axon diameter compared with those in the NGF group, and there were statistically significant differences between the 2 groups.
b In addition, there were also statistically significant differences in MOD and IOD as well as myelinated axon counts between the 2 groups at the 2 time points.