Neither L-arginine nor L-NAME affects neurological outcome after global ischemia in cats.
OBJECTIVE
We attempted to determine whether N-nitro-L-arginine methyl ester (L-NAME) would improve neurological outcome and whether L-arginine (L-ARG) would worsen neurological outcome after transient global ischemia.


METHODS
Halothane-anesthetized cats (n = 6 for each group) were treated with intravenous saline, L-NAME (5 mg/kg or 10 mg/kg), or L-arginine (300 mg/kg) 30 minutes before 10 minutes of ischemia (temporary ligation of the left subclavian and brachiocephalic arteries with hemorrhagic hypotension to 50 mm Hg). At 30 minutes of reperfusion, cats in the L-ARG group were administered an additional 300 mg/kg dose of intravenous L-arginine.


RESULTS
Time (mean +/- SE) to isoelectric electroencephalography was similar among groups (saline, 26 +/- 11 seconds; L-NAME-5, 15 +/- 4 seconds; L-NAME-10, 36 +/- 27 seconds; and L-ARG, 22 +/- 7 seconds). At 72 hours, reperfusion pathological injury was severe and neurological deficit score (mean, range) was similar among groups (saline, 38[11 to 70]; L-NAME-5, 52 [40 to 73]; L-NAME-10, 47 [23 to 70]; and L-ARG, 40 [0 to 79]).


CONCLUSIONS
Nitric oxide is not important in the mechanism of brain injury after global ischemia in cats.
Kirsch
J R
JR
Department of Anesthesiology, Johns Hopkins Medical Institutions, Baltimore, Md. 21287-4963, USA.
Bhardwaj
A
A
Martin
L J
LJ
Hanley
D F
DF
Traystman
R J
RJ
D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D002545:Brain Ischemia / Q000503:physiopathology*; D002415:Cats; D016923:Cell Death / Q000502:physiology; D004569:Electroencephalography; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006624:Hippocampus / Q000187:drug effects / Q000473:pathology; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology*; D009420:Nervous System / Q000187:drug effects* / Q000503:physiopathology*; D015427:Reperfusion Injury / Q000473:pathology
D004791:Enzyme Inhibitors; D001120:Arginine; D019331:NG-Nitroarginine Methyl Ester