Protective effect of adenosine against neuronal injury induced by middle cerebral artery occlusion in rats as evidenced by diffusion-weighted imaging

In the present study, adenosine, an inhibitory neuromodulator, was studied in male Wistar rats subjected to 2 h of transient middle cerebral artery (MCA) occlusion. Adenosine (500 mg/kg ip) was administered twice-once at the time of MCA occlusion and again at the time of reperfusion-and evaluated for its protective effect by using diffusion-weighted imaging (DWI) (30 min after reperfusion). After the DWI experiments, one group of animals was euthanized 2 h after reperfusion for the estimation of oxidative stress markers, while in another group, neurological deficit was assessed 24 h after MCA occlusion. In the adenosine-treated group, percent hemispheric lesion area (%HLA) in DWI was significantly attenuated (11.7+/-5.2) as compared to vehicle-treated group (21.4+/-4.7). The level of malondialdehyde (MDA) (301.8+/-22 nmol/g wet tissue) in the adenosine-treated group was significantly decreased as compared to that in the vehicle-treated MCA-occluded rats (420+/-20 nmol/g wet tissue). An insignificant change was observed in the levels of glutathione in both the vehicle-treated MCA-occluded and the adenosine-treated groups. The neurological deficit was significantly improved in the adenosine-treated group (1.8+/-0.06) as compared to the vehicle-treated (2.9+/-0.38) group. This is the first study to demonstrate the effectiveness of adenosine using DWI in the MCA-occluded rats.