Inhibition of ischemic brain edema formation by post-ischemic administration of a prostaglandin oligomer

We studied the efficacy of an oligomeric derivative of prostaglandin E₁ in protecting the rat brain against focal ischemia. The degree of ischemic damage was evaluated from three parameters, namely, the degree of edema formation, reduction of motor performance, and memory disturbance as measured by a passive avoidance test. The pre-ischemic administration of the drug (6 mg/kg i.p.) had some effects, but the differences were not significant. The post-ischemic administration (6 mg/kg i.p.) produced significant improvement in all three parameters. The increase of water content of the ischemic hemisphere was reduced (p<0.05); the total motor score was improved (p<0.01); and the memory disturbance as estimated by the passive avoidance test was reduced (p<0.01). A possible mechanism of protection is discussed.