Microsurgical intraluminal middle cerebral artery occlusion model in rodents.
OBJECTIVE
Focal brain ischemia induced in rodents by occlusion of the middle cerebral artery (MCA) is a widely used paradigm of human brain infarct. The objective of this study is to compare the effectiveness and reproducibility of MCA filament occlusion model in rats and mice.


METHODS
A total of 140 rodents (69 rats and 71 mice) were operated. Ninety-five animals were subjected to MCA occlusion; the surgical procedure consisted of introducing an uncoated surgical nylon monofilament into the cervical common carotid artery (CCA) and advancing it intracranially to permanently block blood flow into the right MCA. Forty-five sham-occluded rodents underwent CCA ligation. Surgical success, autopsy confirmed success and mortality rate were evaluated. Effective MCA occlusion was confirmed by the evidence of motor neurological deficit, by histopathology, immunohistochemistry (IHC) and reverse transcriptase-polymerase chain reaction (RT-PCR). IHC was performed in a randomly selected number of animals to detect the protein product of monocyte chemoattractant protein-1. The brain tissue in mice was examined by RT-PCR for the expression of macrophage inflammatory protein-1 alpha mRNA.


RESULTS
Surgical success rate was 89% in the rats, significantly lower than that in the mice (100%, P < 0.05). Autopsy confirmed success rate in the rats, 60%, was also significantly different from that in the mice (92.5%, P < 0.001). The operative mortality rate was 4.3% in the rats and 15% in the mice.


CONCLUSIONS
The present study demonstrates that the microsurgical filament occlusion of the MCA can be more successfully performed in mice. The lower rate of success in rats seems to be as a result of the architecture of the carotid canal in this animal. No previous reports, using a considerable number of animals, have compared the feasibility of intraluminal model in the rat with that in the mouse.
Ardehali
M R
MR
National Center of Scientific Research, CNRS, UPR 9023, Montpellier, France. ardehali_mr@yahoo.fr
Rondouin
G
G
D000818:Animals; D002545:Brain Ischemia; D004195:Disease Models, Animal; D007150:Immunohistochemistry; D020244:Infarction, Middle Cerebral Artery; D008297:Male; D051379:Mice; D008866:Microsurgery / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction