Neuroprotective effect of ONO-1078, a leukotriene receptor antagonist, on transient global cerebral ischemia in rats.

AIM To determine whether ONO-1078 [pranlukast, 4-oxo-8-[p-(4-phenylbutyloxy)benzoyl-amono]-2-(tetrazol-5-yl)-4H-1-benzopyran hemihydrate], a potent leukotriene receptor antagonist, possesses a neuroprotective effect on global cerebral ischemia in rats, and to explore its possible mechanism of action. METHODS Transient global cerebral ischemia was induced by four-vessel occlusion for 10 min and followed by 72-h reperfusion. ONO-1078 (0.03-0.3 mg/kg) and edaravone (MCI-186, 3-methyl-1-phenyl-2-pyrazolin-5-one, a neuroprotective agent) 10 mg/kg were ip injected 30 min before ischemia and 1 h after reperfusion, and once a day afterward. Neurological outcome was evaluated before ischemia and 24, 48, 72 h after reperfusion. Neuron density, the expressions of N-methyl-D-aspartate (NMDA) receptor subunit proteins (NR1, NR2A, NA2B) and vascular cell adhesion molecule 1 (VCAM-1) in the cerebral cortex and hippocampus were measured at 72 h after reperfusion. RESULTS ONO-1078 (0.1, 0.3 mg/kg) and edaravone (10 mg/kg) improved ischemia-induced neurological deficiency and reduced neuron death. ONO-1078 (0.1, 0.3 mg/kg) significantly inhibited the enhanced expression of NMDA receptor subunit protein NR2A in the cortex and VCAM-1 in the hippocampus of ischemic rats. CONCLUSION ONO-1078 possesses a neuroprotective effect on global cerebral ischemia in rats, and its mechanism may be partly related to the inhibition of the upregulation of NR2A and VCAM-1 in different regions of the brain.