title: Effect of sildenafil on peripheral nerve regeneration.
abstract: In this study, we investigated whether sildenafil, a cyclic guanosine monophosphate-dependent phospodiesterase-5 inhibitor, could promote functional nerve regeneration after surgical section and repair of the sciatic nerve in rats. Nerve regeneration was studied in a rat sciatic nerve transected and repair model. The animals were randomly assigned to one of the following 3 treatment groups (n = 20/group): sildenafil-treated group 1 (5 mg/kg/d subcutaneously, for 7 days), sildenafil-treated group 2 (5 mg/kg/d subcutaneously, for 42 days), and control group given saline solution (once per day subcutaneously). Walking track analysis, electromyography, and histological evaluation were performed on day 90 after repair operation. The results showed that the sciatic functional index of sildenafil-treated group 1 (data) was slightly better than that of sildenafil-treated group 2 (data) and control group (data) on postoperative day 90. However, the difference was not statistically significant (P = 0.073). No significant differences of the motor nerve conduction velocity were found between experimental groups [18 (2.4) and 20 (4.1 m/s)] and saline control group [19.5 (3.0) m/s] (P = 0.68). Comparison of myelinated axon count of regenerated nerve of the rat between the sildenafil-treated group 1, sildenafil-treated group 2, and saline group was also not significantly different (P = 0.56). In conclusion, administration of sildenafil after nerve repair surgery was found to have positive but insignificant effects on several parameters of nerve regeneration. Further studies could clarify this trend suggesting enhanced nerve regeneration mediated by sildenafil.
authors.affiliation: Division of Plastic Surgery, University of Mississippi Medical Center, Jackson, MS, USA.
authors.forename: Taolin
authors.initials: T
authors.lastname: Fang
authors.forename: Yunchao
authors.initials: Y
authors.lastname: Shao
authors.forename: Tanya
authors.initials: T
authors.lastname: Oswald
authors.forename: William C
authors.initials: WC
authors.lastname: Lineaweaver
authors.forename: Feng
authors.initials: F
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001369:Axons / Q000187:drug effects / Q000502:physiology; D003131:Combined Modality Therapy; D004334:Drug Administration Schedule; D004576:Electromyography; D007279:Injections, Subcutaneous; D008297:Male; D009416:Nerve Regeneration / Q000187:drug effects*; D009431:Neural Conduction / Q000187:drug effects / Q000502:physiology; D059348:Peripheral Nerve Injuries / Q000188:drug therapy* / Q000601:surgery; D058986:Phosphodiesterase 5 Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D010879:Piperazines / Q000494:pharmacology* / Q000627:therapeutic use; D011687:Purines / Q000494:pharmacology / Q000627:therapeutic use; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function; D012584:Sciatic Nerve / Q000187:drug effects / Q000293:injuries* / Q000502:physiology / Q000601:surgery; D000068677:Sildenafil Citrate; D013450:Sulfones / Q000494:pharmacology* / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D058986:Phosphodiesterase 5 Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate