Regional cerebral blood flow during acute ischemia Correlation of autoradiographic measurements with observations of cortical microcirculation

SUMMARYThe right middle cerebral artery was occluded in 10 squirrel monkeys. After the development of ischemic changes in the superficial microvasculature, measurements of regional cerebral blood flow (CBF) were made throughout both cerebral hemispheres by an autoradiographic method using ¹⁴C-labeled antipyrine. In all animals, regions of decreased CBF were found superficially and deep in the ischemic hemispheres. Ischemic changes in surface vessels correlated well with CBF of the underlying cortex, but the degree and extent of ischemia in deeper regions of the brain showed considerable variation and did not correlate with surface changes. Areas of hyperemia or increased CBF were found adjacent to areas of ischemia in five animals. Dr. Martin Reivich of the University of Pennsylvania provided the computer program for the calculations of regional CBF. Dr. George Isaacs of the National Institutes of Health provided the original plastic disks containing antipyrine-I4C for determination of the tissue concentrations of the diffusible indicator from the autoradiographs. Technical assistance was provided by Mr. Robert E. Anderson.