Neuroprotective effects of guanosine on stroke models in vitro and in vivo.

Deprivation of oxygen and glucose for 5h induces apoptosis in SH-SY5Y neuroblastoma cell cultures. After combined glucose and oxygen deprivation (CGOD) addition of guanosine (100 microM), a non-adenine-based purine nucleoside, significantly reduced the proportion of cells undergoing apoptosis. To determine whether guanosine was also neuroprotective in vivo, we undertook middle cerebral artery occlusion (MCAo) on male Wistar rats and administered guanosine (8mg/kg), intraperitoneally, or saline (vehicle control) daily for 7 days. Guanosine prolonged rat survival and decreased both neurological deficits and tissue damage resulting from MCAo. These data are the first to demonstrate that guanosine protects neurons from the effects of CGOD even when administered 5h after the stimulus, and is neuroprotective in experimental stroke in rats.