Experimental Cerebral Microembolism

Abstract

Cerebral microembolism with carbon microspheres was studied by simultaneous radioactive tracer determination of the red blood cell, albumin, iodoantipyrine, and pertechnetate spaces in the rat brain. Brain edema was evident begining at four hours after embolization and was associated with decreased cerebral blood volume. Early edema was not accompanied by abnormal capillary permeability to macromolecules; however, the albumin space was increased at later times. Increases in the whole brain and the more heavily embolized right hemisphere pertechnetate spaces developed prior to similar changes in the albumin space. The iodoantipyrine space did not reliably reflect total brain water possibly due to rapid hepatic deiodination of this molecule. Our results suggest that multiple radioactive isotope label space estimation can serve as a sensitive tool for evaluation of pathophysiologic changes in ischemic brain injury.