[The effects of nitric oxide synthase on secondary spinal cord injury: an experimental research].
OBJECTIVE
To investigate the effects of the changing amount of nitric oxide on secondary spinal cord injury and determine the role of nitric oxide during secondary spinal cord injury.


METHODS
After close spinal cord modest injury (T9) by fluid-percussion model, rats were given saline, small dose of L-NAME (8 mg/kg) and large dose of L-NAME (40 mg/kg) respectively. The changes of hemodynamics, tissue constitution, and neural function were observed.


RESULTS
We found small dose of L-NAME had little effects on the hemodynamics but could improve neural function. Whereas, large dose of L-NAME raised the MABP significantly, constricted pial arteriole (90 minutes, 10%), decreased regional spinal cord blood flow (SCBF) (90 minutes, 22%), augmented the dysfunction of neural system. Rats lost weight and the rate of death raised.


CONCLUSIONS
These findings indicated that nitric oxide could have dual role during secondary spinal cord injury. Controlling local nitric oxide production suitably through changing the activity of nitric oxide synthase could improve tissue survival and benefit the recovery of neural function.
Department of Orthopedics, Shanghai Changzheng Hospital, Second Military Medical University.
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Zhao
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Li
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Sun
D000818:Animals; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology*; D009569:Nitric Oxide / Q000502:physiology; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D052248:Nitric Oxide Synthase Type I; D051381:Rats; D017207:Rats, Sprague-Dawley; D013119:Spinal Cord Injuries / Q000201:enzymology* / Q000628:therapy
D004791:Enzyme Inhibitors; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; C496322:Nos1 protein, rat; D019331:NG-Nitroarginine Methyl Ester