[Evaluation of hemodynamic reserve capacity of a chronic cerebral ischemia model in rat by reflectance spectrophotometric technique].
The hemodynamics of chronic cerebral ischemia has not well been studied compared to that of acute cerebral ischemia. We assessed the capacity of the hemodynamic reserve of chronic cerebral ischemia in a rat carotid-jugular arteriovenous shunt model. Eight to 12 weeks after creation of the arteriovenous shunt, the sequential changes of concentration and oxygen saturation of hemoglobin (Hb) in the both parietal cortices under resting and hypercapnic conditions were spectrophotometrically measured through a thinned skull window. The relative blood flow index (BFI) was calculated from the chronological concentration curve of indocyanine green (ICG) for evaluation of regional cortical blood flow (rCBF). These procedures were repeated after the shunt closure. Hb oxygen contents for saturation, total Hb concentration during hypercapnia, and BFI on the shunt side were lower than those on the contralateral side. They increased, however, after the closure. These findings showed that capacity of hemodynamic reserve impaired due to chronic cerebral ischemia could be improved by an increase of perfusion pressure.
Noujou
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Department of Neurosurgery, Hokkaido University School of Medicine, Sapporo, Japan.
D000818:Animals; D001166:Arteriovenous Shunt, Surgical; D002545:Brain Ischemia / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D002908:Chronic Disease; D004195:Disease Models, Animal; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D015424:Reperfusion; D013053:Spectrophotometry / Q000379:methods