Cerebral ischemia in gerbils: polyribosomal function during progression and recovery.

Cerebral ischemia was produced by clipping the right common carotid artery in Mongolian gerbils. Polyribosomal function in cerebral ischemia during progression and recovery was studied by investigation of morphology (electronmicroscopy), physical property (size distribution profiles) and biochemical property (polypeptide synthesis). Polyribosomes and their function were relatively well preserved during progression of ischemia. The most striking finding was an extensive disaggregation of polyribosomes and suppression of polypeptide synthesis immediately after re-establishment of cerebral circulation. These phenomena occurred not only with irreversible ischemia at 3 h but also with reversible ischemia at 30 min. In the latter, disaggregation of polyribosomes gradually recovered, but no tendency for recovery was observed after an ischemic period of 3 h. The disaggregation and delay in reaggregation of ribosomes after re-establishment of cerebral circulation may be a significant factor in the irreversibility of cerebral ischemia. The observed deterioration of cellular function during the recovery process may have an important implication not only for medical management of stroke but also for surgical recirculation during acute stroke.