Superoxide dismutase and catalase failed to improve neurologic outcome after complete cerebral ischemia in the dog.
Superoxide dismutase (SOD) and catalase, natural scavengers of free oxygen radicals, or saline were administered as a continuous systemic infusion to 12 dogs, in a blind randomized fashion, starting 10 min prior to a 10-min episode of complete cerebral ischemia, and continued thereafter for 60 min. Reversible complete cerebral ischemia was achieved by simultaneously occluding the ascending aorta and venae cavae. There were no significant differences in physiological variables (arterial blood gases, hemoglobin, mean arterial blood pressure, heart rate, and temperature) between the two groups, either pre-ischemia or post-ischemia. There was no significant difference in neurologic outcome when evaluated at 48 h post-ischemia. It has previously been reported that the same dose of SOD and catalase as used in the current study could reduce infarct size by 50% when given systemically before reperfusion following coronary ischemia in dogs. The lack of a measurable effect on neurologic outcome in our cerebral ischemic model might be because of the failure of the free oxygen radical scavengers to reach the ischemic cells in sufficient amounts, or because free oxygen radicals do not contribute to brain injury following complete cerebral ischemia.
Forsman
M
M
Department of Anesthesiology, Mayo Medical School, Rochester, Minnesota.
Fleischer
J E
JE
Milde
J H
JH
Steen
P A
PA
Michenfelder
J D
JD
D000818:Animals; D002545:Brain Ischemia / Q000188:drug therapy*; D002374:Catalase / Q000627:therapeutic use*; D004285:Dogs; D005260:Female; D008297:Male; D009460:Neurologic Examination; D013482:Superoxide Dismutase / Q000627:therapeutic use*
D002374:Catalase; D013482:Superoxide Dismutase