The Distribution and Density of Reduced Cerebral Blood Flow Following Acute Middle Cerebral Artery Occlusion: An Experimental Study by the Technique of Hydrogen Clearance in Baboons

Abstract

Abstract:The Distribution

Focal Cerebral Ischaemia in the Rat: 2. Regional Cerebral Blood Flow Determined by [14C]Iodoantipyrine Autoradiography following Middle Cerebral Artery Occlusion

“…Similar but less extensive reductions in blood flow in the cortical territory of the anterior cerebral artery were observed in cats by Ginsberg et al (1976; 65-68% compared with the contralateral hemisphere) and in baboons (Symon et al, 1974;84% of pre-occluded CBF). In the present study, reductions in blood flow by 20-40% of values in sham-operated animals were also seen in the parts of the opposite hemisphere, but these were statistically significant only in the anterior cingulate cortex.…”

“…The severity of reductions in blood flow in the cerebral cortex appears to be generally similar in the rat to those observed in cats with middle cerebral artery occlusion (Ginsberg et al, 1976) but may be proportionally more extensive than observed in primates (Blair and Waltz, 1970;Symon et al, 1974). In each of these other species, the levels of blood flow during middle cerebral artery occlusion have been correlated with subsequent neuropathological findings.…”

“…1, 1981 neuropathological data are available only for animals killed 2 h after occlusion . Despite this discrepancy, it is still feasible to compare the results of the two studies, because serial measurements of blood flow have shown that after occlusion of the middle cerebral artery, the level of blood flow remains stable for at least the next 1-2 h provided that systemic conditions do not fluctuate (Symon et al 1974;Tamura et al, 1980). Such variations were excluded by the careful physiological control of the animals in our studies.…”

“…In the present study there was no sign of a zone of relatively or absolutely increased blood flow in the cerebral cortex around the central ischaemic area. Indeed, although Ginsberg et al (1977) showed that a zone of enhanced glycolysis does surround the area of ischaemia produced by occlusion of the middle cerebral artery, there is little experimental evidence that a marginal zone of hyperaemia develops, provided that conditions remain stable (Symon et al, 1974). Waltz (1968) believed that the reddening of venous blood that they observed in the pial circulation in focal ischaemia could be attributed in part to luxury perfusion, but they found this difficult to reconcile with their observation that the phenomenon was only rarely associated with an absolute increase in local blood flow.…”

Paradoxical reduction of cerebral blood flow after acetazolamide loading: a hemodynamic and metabolic study with 15O PET

“…Paradoxical reduction of cerebral blood flow (CBF) after administration of vasodilators, termed the "intracerebral steal phenomenon", was originally described in the core of an acute brain infarct after CO 2 inhalation in a cat experimental model [1,2] . The vasodilator acetazolamide (ACZ) also reduces CBF in the core of the acute ischemic region after experimental occlusion of the middle cerebral artery (MCA).…”