[Effect of perfluorochemicals on experimental cerebral ischemia]

It has been noted that perfluorochemicals (PFC) which were developed as artificial blood substitutes, protect against ischemic brain injury by their ability to serve as oxygen carriers. It is also known that normovolemic hemodilution (HD) improves cerebral blood flow (CBF) and neurological symptoms in cerebral infarction. However, there are few reports concerning the effect of PFC on the collateral circulation via pial anastomoses in cases of middle cerebral artery (MCA) occlusion. The ability to record the pial arterial blood pressure (PAP) without interfering blood flow now makes it possible to measure the segmental resistance of cerebral vessels. By using this method, one can measure collateral vessel resistance through pial anastomoses following MCA occlusion. In this paper, we studied the protective effects of PFC combined with HD on ischemic brain injury with the focus on the collateral circulation via pial anastomoses following occlusion of the MCA. Twenty adult cats were studied: control, 8; HD, 5; Fluosol (Fluosol-DA), 7. The systemic arterial pressure (SAP) and PeCO2 were continuously monitored. Subsequently the MCA was occluded via the transorbital approach. CBF in the ectosylvian gyrus (central area of the ischemic lesion) was measured by the hydrogen clearance method. A small pial artery about 100 microns in diameter on the exposed ectosylvian gyrus was punctured nonocclusively with a micropipette filled with 2 M sodium chloride which was connected to a servo-null micropressure system (Model 900, W-P Instruments, Inc. U.S.A.). The electroencephalogram (EEG) was recorded from the ectosylvian gyrus.(ABSTRACT TRUNCATED AT 250 WORDS)