RBC filterability, oxygen saturation, ATP intracellular stock, and cerebral microcirculation.

The filterability of erythrocytes through Nucleopore filters of 5 micrometer has been studied with a new device (Hemorheometer SPO1). A reliable and reproducible index of filterability (IF) can be obtained which depends only on the red blood cell deformability. The results showed an alteration of red blood cell deformability in some pathological circumstances like smoking and that deformability depends on the nature of haemoglobin, the ATP intracellar stock and the saturation of haemoglobin by oxygen. The cerebral microcirculatory consequences of alterations of red blood cell deformability has been studied in vitro by measuring whole blood filterability on 5 micrometer Nucleopore filters with the classical technic of Reid & Dormandy and in vivo by 99mTc cineangioscintigraphy and by determination of the regional cerebral blood flow by the 133Xenon inhalation technic. The results showed an increase of cerebral ascensional time and mean transit time of the cineangioscintigraphy and a decrease of regional cerebral blood flow in patients presenting with a decrease of whole blood filterability flow.