FK506 increases the regeneration of spinal cord axons in a predegenerated peripheral nerve autograft.
The authors examined the ability of FK506 to accelerate axonal regeneration of rat spinal cord axons in a peripheral nerve (PN) graft. Predegenerated autografts were produced by transecting the left tibial nerve 1 week prior to spinal cord implantation into the lumbar (L-3-L-4) spinal cord. Rats were given daily injections of either FK506 (5 mg/kg, subcutaneous) or vehicle for 21 days. The PN grafts from FK506-treated rats contained larger sized regenerating axons compared with vehicle-treated controls, and mean axonal areas increased by 25% at 7.5 mm along the PN graft. Fluoro-Gold retrograde labeling confirmed that the regenerating axons originated from the central nervous system. Unexpectedly, the majority (>50%) of neurons in the red nucleus were retrogradely labeled in the FK506-treated animals only. The results indicate that FK506 not only accelerates the elongation of spinal cord axons but also promotes regeneration of rubrospinal neurons.
Wang
M S
MS
Center for Research on Occupational and Environmental Toxicology, Oregon Health Sciences University, Portland 97201-3098, USA.
Gold
B G
BG
D000818:Animals; D001369:Axons / Q000187:drug effects* / Q000473:pathology; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D008297:Male; D008854:Microscopy, Electron; D009410:Nerve Degeneration / Q000473:pathology*; D009416:Nerve Regeneration / Q000187:drug effects*; D009434:Neural Pathways / Q000187:drug effects / Q000473:pathology; D009474:Neurons / Q000187:drug effects / Q000473:pathology; D010525:Peripheral Nerves / Q000637:transplantation*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012012:Red Nucleus / Q000187:drug effects / Q000473:pathology; D013116:Spinal Cord / Q000187:drug effects / Q000473:pathology; D013119:Spinal Cord Injuries / Q000473:pathology*; D016559:Tacrolimus / Q000494:pharmacology*
D007166:Immunosuppressive Agents; D016559:Tacrolimus