Original Article

OBJECTIVE: This study planned to evaluate the effects of vitamin A (VA) and steroid treatment on nerve healing. Study design: we investigated electrophysiological, electron microscopic (EM), immunohistochemical, and biochemical findings in rat sciatic nerve model. MATERIALS and METHODS: In total, 112 female rats were divided into 16 groups, each consisting of 7 animals. Subjects were evaluated accord-ing to compound muscle action potential (CMAP) findings, ultrastructural staging of myelinated axons with EM, nitric oxide (NO) and malondi-aldehyde (MDA) findings in serum and tissue, and immunohistochemical findings in the first week and first month. RESULTS: NO and MDA levels in serum and tissue were found to be statistically lower after high-dose methylprednisolone (MP), normal-dose MP, high-dose MP+VA, normal-dose, and MP+VA treatment modalities compared to controls (p<0.05). The most similar EM findings compared to control animals were seen in the normal-dose MP and high-dose MP+VA treatment groups. The best amplitude values were seen in the high-dose MP and continuous normal-dose MP therapy groups in the first month. In the normal-dose MP and high-dose MP+VA treatment groups, intense staining was found compared to the control and sham groups according to the sciatic nerve immunohistochemical examination. CONCLUSION: This study revealed noticeable VA effects on the inflammatory process during the healing of traumatic nerve paralysis by electron microscopy and immunohistochemistry. However, similar findings were not established by electrophysiology. Therefore, more experimental studies are needed to further investigate the efficacy and the mechanism of action of VA on steroid administration and the inflammatory process