THE SEVERITY OF POSTISCHEMIC HYPOPERFUSION INCREASES WITH DURATION OFCEREBRAL-ISCHEMIA IN RATS

Regional cerebral blood flow was studied after a period of hypotensive bilateral carotid occlusion in rats. As other studies have found, we confirm that 15 min of ischemia caused an initial brief hyperemic epis ode followed by severe hypoperfusion in all areas. With varying durati on of ischemia from 5 to 10, 15 and 20 min, the median cerebral blood flow 60 min postischemia was 79%, 46%, 48% and 34% of control, respect ively. Thus the degree of postischemic hypoperfusion increased signifi cantly with the duration of ischemia.