Effect of vitamin D on axonal regeneration after the epineural devascularization of sciatic nerve

In this study it was aimed to investigate the effect of vitamin D3 after the epineural devascularization of sciatic nerve. In our study 40 adult (~200-250 gr), female, Wistar rats were used. Rats were randomized into 4 main groups: Group 1 (Control), Group 2 (Sham), Group 3 (Epineural devascularization + vitamin D3), Group 4 (Epineural devascularization). In Group 1, sciatic nerves were used to determine its normal morphological and physiological characteristics. In Group 2, sciatic nerve and its 3 branches were exposed; excipient was administered. In Group 3, epineural devascularization was applied on sciatic nerve and vitamin D3 was administered by oral route. In Group 4, epineural devascularization was applied on sciatic nerve. Regeneration levels were analyzed by functional (sciatic functional index, pinch test and biochemical analyses) and morphological (electron microscopic analysis and wet muscle weight) analyses. At the end of the 4th postoperative week, vitamin D3 administration was found to have a statistically significant effect on functional analysis data and wet muscle weight values between Group 3 and Group 4 (p <0,05). In electron microscopic analysis, there were more myelin residues in group without vitamin D3 treatment (Group 4); on the other hand in vitamin D3 treated group (Group 3) numerous remyelinized nerve fibres with thin myelin sheat were observed. Those remyelinized nerve fibres have thicker and better form compared to group without vitamin D3 treatment (Group 4). As a result it was showed that vitamin D3 is an effective neuroregenerative agent in ischemic peripheral nerve injuries. Keywords: Epineural devascularization, peripheral nerve injury, sciatic nerve, vasa nervorum, vitamin D.