Reversal of ischemic-induced chronic memory dysfunction in aging rats with a free radical scavenger-glycolytic intermediate combination.

Rats were subjected to bilateral carotid artery occlusion (2-VO) or sham occlusion (No-VO) and tested 12 weeks for visuo-spatial memory (VSM) function. After 14 weeks, 2-VO rats (N = 4) showing severe visuo-spatial memory impairment were given dimethyl sulfoxide (DMSO)-fructose 1,6-diphosphate (FDP) i.p. for seven days and retested on the water maze. After DMSO-FDP, a 54% improvement in their VSM was seen which nearly reached control No-VO values. Untreated 2-VO (N = 4) and No-VO (N = 8) rats showed no significant changes in their VSM. DMSO-FDP treatment was discontinued and rats were retested on the water maze but improvement was lost and VSM function regressed to pretreatment levels. Immunohistochemical examination showed minimal neuronal damage in all 2-VO rats and slight loss of microtubule associated protein-2. Glial fibrillary acidic protein immunostaining increase was observed only in untreated 2-VO rats. The results indicate that a DMSO-FDP combination improves VSM secondary to chronic brain hypoperfusion.