OBJECTIVE

To investigate the neuroprotective effect of preconditioning with cannabinoid (CB) receptor agonist WIN 55, 212 - 2 on focal cerebral ischemia.

METHODS

Fifty male SD rats were randomly assigned to 5 equal groups: control group undergoing middle cerebral artery occlusion (MCAO) for 2 h only without any preconditioning; 3 WIN 55, 212 - 2 preconditioning groups (WIN1-3) injected intraperitoneally with WIN 55, 212 - 2 at the doses of 0.3, 1, and 3 mg/kg respectively 24 h before MCAO for 2 h, and DMSO group injected intraperitoneally with dimethyl sulfoxide (DMSO), solvent of WIN 55, 212 - 2 24 h before MCAO for 2 h. 24, 48, and 72 hours after reperfusion the neurological function score (NFS) was evaluated the rats were then decapitated with their brains taken out. Brain infarct volume was evaluated with 2% 2, 3, 5-triphenyltetrazolium chloride (TTC) staining.

RESULTS

The NFS values of the rats in WIN 55, 212 - 2 preconditioning groups were all significantly higher than those of the control and DMSO groups (all P < 0.05) while the infarct volumes of the WIN 55, 212 - 2 preconditioning groups were all significantly smaller than those of the control and DMSO groups (all P < 0.05) 24, 48, and 72 h after reperfusion. The infarct volumes of the WIN2 and WIN3 groups were both significantly smaller than that of the WIN1 group (both P < 0.05). However, there was no significant difference in the infarct volume between WIN2 and WIN3 groups (P = 0.928).

CONCLUSIONS

WIN 55, 212 - 2 preconditioning has neuroprotective effect on focal cerebral ischemia with a dose-dependent manner.