Keep warm and get success: the role of postischemic temperature in the mouse middle cerebral artery occlusion model.

Intraluminal suture middle cerebral artery occlusion (MCAO) model is the most frequently used model for ischemic stroke. However, the success rate of this model is variable among different research studies. This study aimed to investigate the effect of postischemic temperature on the success rate. A total of 100 C57BL/6 mice were randomized into two groups: control group (n=50), body temperature was allowed to self-regulate after MCAO; temperature-controlled group (n=50), mice were kept warm in an incubator for 12 h after MCAO. The body temperature of animals was measured before, during, and for 12 h after MCAO. Neurological deficits and infarct volumes were measured at 24 h after MCAO. There was significant difference (P<0.05) of the body temperature between the two groups from 0.5 h to 3.5 h post ischemia. Moreover, there was obvious difference between the success rates of the two groups (control group: 52%, temperature-controlled group: 84%, P<0.05). In the successful models, infarct volume was significantly (P<0.05) higher in temperature-controlled group (53.44%±9.83%, n=42) than control group (45.63%±10.24%, n=26). There was significant difference of the modified neurological severity scores (P<0.05), left adhesive tests (P<0.05) between the two groups. Our data demonstrated that postischemic warming contributed to the success of mouse MCAO model.