Transient middle cerebral artery occlusion in rats as an experimental model of brain ischemia.
OBJECTIVE
To assess a rat model of cerebral ischemia induced by occlusion of the middle cerebral artery and its effect on the area of cerebral infarction.


METHODS
Brain ischemia was induced in 52 male Wistar rats by introduction of a 3-0 nylon suture into the middle cerebral artery for either 90 (n=28) or 120 (n=24) minutes. Ischemic injury volume was determined by TTC staining, digital photography and analysis with the Image J software. Statistical analysis employed Student's t test and the Mann-Whitney U test.


RESULTS
The groups were similar in terms of weight (p=0.59). The length of thread inserted was 14.7 mm in the 90 min group and 20.2 mm in the 120 min group (p=0.37). Ischemic injury was detected in 11 animals (39%) after 90 min and 11 (45%) after 120 min (p=0.77). In animals exhibiting injury, filament length was 16.1 ± 11 mm (90 min) vs. 21.9 ± 7.4 mm (120 min) (p=0.15). The mean infarction zone volume was greater after 120 (259.2 mm³) than after 90 min (162.9 mm³) (p=0.04). The neurological deficit score for the 90 and 120 min groups was 2.0 and 2.4, respectively (p=0.84).


CONCLUSIONS
The experimental model induced significant ischemic cerebral injury in both groups.
Calloni
Renato Luis
RL
Department of Clinical Surgery, UCS, Caxias do Sul, Brazil. rcalloni@terra.com.br
Winkler
Bruno Costamilam
BC
Ricci
Guilherme
G
Poletto
Marcos Giacomelli
MG
Homero
Wagner Martins
WM
Serafini
Eduardo Pretto
EP
Corleta
Oly Campos
OC
D000818:Animals; D002545:Brain Ischemia / Q000209:etiology / Q000473:pathology; D004195:Disease Models, Animal; D008297:Male; D020768:Middle Cerebral Artery / Q000601:surgery*; D009460:Neurologic Examination; D051381:Rats; D017208:Rats, Wistar; D018709:Statistics, Nonparametric; D013537:Sutures; D013997:Time Factors