Effects of L-arginine and NG-nitro L-arginine methyl ester on lipid peroxide, superoxide dismutase and nitrate levels after experimental sciatic nerve ischemia-reperfusion in rats.
Nitric oxide (NO) has been reported to function in both cytoprotective and cytotoxic tissue ischemia-reperfusion (I/R). In this study, we evaluated the effects of L-arginine, the substrate for NO, and NG-nitro L-arginine methyl ester (L-NAME), NO synthase (NOS) inhibitor on super  oxide dismutase (SOD) enzyme activity, malondialdehyde (MDA), a marker of lipid peroxidation, nitrate levels, and histopathological structure in rat sciatic nerve 2 h after ischemia, followed by 3 h of reperfusion. Reperfusion resulted in a significant increase in lipid peroxidation level and a decrease in nitrate level of the sciatic nerve. The increased level of lipid peroxidation was partly reduced by NOS inhibition. The decrease in sciatic nerve SOD level, observed in group subjected to I/R, was prevented by inhibition of NOS by L-NAME. These results were supported by histological findings that in the L-arginine-treated group, degenerations of both myelin sheath and axon were observed, while in the L- NAME-treated group, no pathological changes were detected. Our results suggested that excessive NO formation accelerates lipid peroxidation, as well as axonal degeneration on the early reperfusion period of the sciatic nerve.
Sayan
Hale
H
Zonguldak Karaelmas, University of Faculty of Medicine, Department of Physiology, Zonguldak, Turkey. halesayan@yahoo.com
Ugurlu
Belgizar
B
Babül
Aydan
A
Take
Gulnar
G
Erdogan
Deniz
D
D000818:Animals; D001120:Arginine / Q000627:therapeutic use*; D004195:Disease Models, Animal; D005260:Female; D006652:Histological Techniques; D007813:Laparotomy / Q000379:methods; D008054:Lipid Peroxides / Q000378:metabolism*; D008297:Male; D008854:Microscopy, Electron; D009186:Myelin Sheath / Q000473:pathology / Q000648:ultrastructure; D019331:NG-Nitroarginine Methyl Ester / Q000627:therapeutic use*; D018696:Neuroprotective Agents / Q000627:therapeutic use; D009566:Nitrates / Q000378:metabolism*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000517:prevention & control*; D012584:Sciatic Nerve / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology / Q000648:ultrastructure; D018709:Statistics, Nonparametric; D013482:Superoxide Dismutase / Q000378:metabolism*; D013997:Time Factors
D008054:Lipid Peroxides; D018696:Neuroprotective Agents; D009566:Nitrates; D001120:Arginine; D013482:Superoxide Dismutase; D019331:NG-Nitroarginine Methyl Ester