Biochemical and histopathological studies on a mouse brain ischemic model induced by bilateral carotid artery occlusion: comparison with the carbon monoxide inhalation method and other ischemic or anoxic models

Bilateral occlusion of the carotid arteries (BCAO) killed 52% of the male ddY mice (N = 86) and 77% of the ICR mice (N = 96) within 10 min, and the mean survival time of the ddY strain recorded for the 10 min was significantly longer than the time of the ICR strain. Among animals that survived longer than 1 hr after BCAO, some (5 of ddY and 3 of ICR) were able to survive for more than 24 hr. All of the neurobehavioral and histopathological signs developed by BCAO and in most cases followed by death were found to be also inducible by unilateral occlusion alone, although this was in a small fraction of mice. The brain levels of ATP, glucose and acetylcholine significantly decreased in mice that died within 10 min after BCAO, while none of these changes were detectable in mice surviving BCAO for 1 hr, just as in mice that died by carbon monoxide or ether inhalation. The results obtained herein indicate that mice may not be homogeneous in the functional level of the collateral route of blood supply to the brain tissue and/or in the sensitivity toward the ischemia-inducible lethality.