Melatonin enhances the in vitro and in vivo repair of severed rat sciatic axons.
This study examines the effects of several experimental compounds [melatonin (MEL), cyclosporin A (CsA), glial-derived neurotrophic factor (GDNF), and methylprednisolone (MP)] on polyethylene glycol (PEG)-induced repair in vitro and/or in vivo by plasmalemmal fusion (PEG-fusion) of sciatic axons severed by crushing. As measured by conduction of compound action potentials (CAPs) through the lesion site, a significantly (p<0.025) higher percentage (75%) of crushed rat sciatic axons can be repaired in vitro by PEG-fusion following exposure to MEL compared to PEG-fusion of severed sciatic axons in control Krebs saline that contains calcium (CTL=20%). In contrast, no other experimental compound (GDNF: 45%; MP: 42%; CsA: 24%) produces a significant improvement in PEG-fusion success compared to CTL. Further, MEL produces significantly (p<0.001) larger peak CAP amplitudes conducted through the lesion site following PEG-fusion compared to CTL or any other experimental compound in vitro. Additionally, MEL significantly (p<0.025) increases the ability to PEG-fuse sciatic axons in vivo, compared to CTL. Finally, PEG-fusion success in vivo is significantly (p<0.01) greater in calcium-free CTL (CTL-Ca) compared to CTL.
Stavisky
Ronda C
RC
Section of Neurobiology, The University of Texas at Austin, 1 University Station 0C0920, Austin, TX, 78712-0248, USA.
Britt
Joshua M
JM
Zuzek
Aleksej
A
Truong
Elizabeth
E
Bittner
George D
GD
D000200:Action Potentials; D000818:Animals; D002118:Calcium / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry; D016572:Cyclosporine / Q000494:pharmacology; D004594:Electrophysiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008550:Melatonin / Q000494:pharmacology*; D008775:Methylprednisolone / Q000494:pharmacology; D009409:Nerve Crush; D009416:Nerve Regeneration / Q000187:drug effects*; D018696:Neuroprotective Agents / Q000494:pharmacology*; D009924:Organ Culture Techniques; D011092:Polyethylene Glycols / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000187:drug effects* / Q000473:pathology; D013501:Surface-Active Agents / Q000494:pharmacology
D003470:Culture Media; D004791:Enzyme Inhibitors; D018696:Neuroprotective Agents; D013501:Surface-Active Agents; D011092:Polyethylene Glycols; D016572:Cyclosporine; D008550:Melatonin; D002118:Calcium; D008775:Methylprednisolone