[Neuroprotective effect of preconditioning with cannabinoid receptor agonist WIN 55, 212 - 2 on focal cerebral ischemia: experiment with rats].

Objective To investigate the neuroprotective effect of preconditioning with eannabinoid (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 WINI group (both P < 0. 05 ). However, there was no significant difference in the infarct volume between WIN2 and WIN3 groups (P = 0. 928). Conclusion WIN 55,212-2 preconditioning has neuroprotective effect on focal cerebral ischemia with a dose-dependent manner. Key words: Ischemic preconditioning;  Focal cerebral ischemia;  Rats ;  Cannabinoid receptoragonist