Objective To investigate if
isoflurane preconditioning induces ischemic tolerance against neuronal damage produced by middle
cerebral artery occlusion (MCAO) in rats Methods Thirty male SD rats weighing 350 400g were randomly divided into three groups: control group (no pretreatment,n=10),
isoflurane preconditioning group (ISO group) (inhalation of 2% isoflurane and 98% O 2 1h per day lasting 5d,n=10), oxygen preconditioning group (O 2 group) (inhalation of 98% O 2 1h per day lasting 5d ,n=10) Right MCAO was induced by a 3 0 nylon thread with round tip inserted cranially into right internal carotid artery under isoflurane anesthesia and maintained for 120 min The neurologic deficit score (NDS) was evaluated 1, 3, 6, 12, 16 and 24h after reperfusion and the infarct volume was calculated at 24th following reperfusion Results The NDS of ISO group was lower than that of other two groups at each time interval (P<0 01) The infarct volume of control, O 2 and ISO group was (147 1±35 7) mm 3, (155 4±32 8) mm 3 and (17 4±20 7) mm 3 respectively The difference between ISO and control groups was significant (P<0 001), but there was no significant difference between O 2 and control groups (P>0 05) Conclusions Isoflurane pretreatment can induce ischemic tolerance against neuronal damage produced by transient MCAO in rats