Nitric oxide synthases II and III and vascular endothelial growth factor are up-regulated in sciatic nerve after spiral cuff electrode implantation

Nerve cuff electrodes, commonly used in functional electrical stimulation systems, induce local morphological changes that can affect nerve functionality. Nitric oxide (NO) and vascular endothelial growth factor (VEGF) have both neural and vascular effects. We investigated the time-dependent regulation of nitric oxide synthases (NOS) and of VEGF after implantation of spiral cuff electrode around rat sciatic nerve. NOSIII as well as VEGF were up-regulated in both epineurial and endoneurial compartments in cuff-implanted animals along with microvascular changes. Our results suggest that VEGF and NO are implied in morphological and functional alterations occurring in the early time after cuff implantation.