Abstract
Aim In this experimental study, we aimed to investigate possible healing effects of memantine
hydrochloride, an N-methyl-d-aspartate (NMDA) antagonist, with clinical, biochemical, and histopathologic
methods on acute peripheral nerve injury (PNI).
Material and Method Forty-eight adult Wistar albino rats were divided into four groups (n = 12). The groups were arranged as sham-operated group (group 1), acute compression
model group (group 2), trauma + low-dose memantine group (group 3), and trauma + high-dose
memantine group (group 4). Memantine was administered intraperitoneally for 7 days.
Subjects were sacrificed after the measurement of the sciatic nerve function index
(SNFI) on the eighth day. Cyclooxygenase 2 (COX-2) and tumor necrosis factor-α (TNF-α)
levels were measured in nerve tissues. Histopathologic evaluation was performed by
electron microscopy.
Results The mean sciatic function index (SFI) scores of groups 1 to 4 were +3.27 (standard
deviation [SD] ±4.66),–18.2 (SD = ±11.7),–8.5 (SD = ±7.5), and–2.5 (SD = ±9), respectively.
The mean COX-2 values were 0.98 ng/mL (SD = ±0.51), 1.89 ng/mL (SD = ±0.22), 1.39
ng/mL (SD = ±0.36), and 1.35 ng/mL (SD = ±0.59), respectively. TNF-α values were 0.09
pg/mL (SD = ±0.23), 1 pg/mL (SD = ±0.96), 0.46 pg/mL (SD = ±0.55), and 0.48 pg/mL
(SD = ±0.78), respectively. Group 1 showed normal histologic findings. Group 2 showed
marked edema particularly in large-diameter myelins. Myelin configurations were detected
in large myelinated axons in group 3. The number of mast cells in endoneurium was
high in group 4.
Conclusion The efficacy of memantine in the acute phase of PNI appears to be significant according
to the SNFI and biochemical tests. However, histologic findings suggest that high
doses of memantine have a negative effect on PNI.
Keywords
peripheral nerve injury - memantine - cyclooxygenase-2
