[The effect of mannitol in preventing the development of cerebral infarction--an electron microscopical investigation (author's transl)].

We have undertaken an electron microscopical investigation of the effects of mannitol on the development of cerebral infarction using an experimental model for thalamic infarction in dogs. 1) It was found that administration of 20% mannitol (2 g/kg) prior to arterial occlusion had significantly suppressive effects upon the formation of cerebral infarction following occlusion. 2) In the control group, only one animal with 30 minutes occlusion showed no pathological changes, but, in the mannitol group, dogs with normal brain tissue were seen even after 120 minutes occlusion. 3) All of the control animals with 60 minutes occlusion showed nerve cell shrinkage, but none of the mannitol treated animals showed such changes. 4) After 180 minutes of arterial occlusion, no notable differences were found between the control and mannitol groups. In one of the mannitol treated animals, cerebral infarction was more severe than in the control group.