The Partition of Trace Amounts of Xenon Between Human Blood and Brain Tissues at 37°C

The relative solubilities of trace amounts of 133Xe at 37° C in human plasma, red blood cells, grey and white matter of the brain, and in homogenized whole brain have been determined. From these data the tissue/blood partition coefficients for cortex, white matter and whole brain have been calculated as a function of haematocrit. On the basis of the measured 133Xe solubilities it is estimated that the human brain consists of 60·3±6·3% grey matter and the remainder white matter.