Stereo-selective neuroprotection against stroke with vitamin A derivatives.

In this study we evaluated the neuroprotective potential of vitamin A (all-trans retinol), and its geometric isomers, all-trans retinoic acid and 9-cis retinoic acid, in a focal model of ischemia. A 60 minute middle cerebral artery occlusion in C57 mice resulted in over 50% hemispheric infarction. Vitamin A (retinol) and its derivatives were administered as two i.p. injections immediately prior to and following ischemia. A reduction in infarct volume was observed with all-trans retinol, in a dose-dependent manner: maximum protection was observed with a 10 mg/kg dose. A similar protective profile was observed with all-trans retinol, but not the stereo-isomer 9-cis retinoic acid. Administration of the derivatives 1 h following ischemia did not produce significant protection. Taken together these data suggest a possible use of vitamin A derivatives as an acute neuroprotective strategy for stroke.