  Among the major factors controlling the cerebral blood flow (CBF), the effect
of PaCO2 is peculiar in that it violates autoregulatory CBF mechanisms and
allows to explore the full range of the CBF. This research resulted in a simple
physical model, with a four parameter formula, relating the CBF to PaCO2. The
parameters can be extracted in an easy manner, directly from the experimental
data. With this model earlier experimental data sets of Rhesus monkeys and rats
were well fitted. Human data were also fitted with this model. Exact formulae
were found, which can be used to transform the fits of one animal to the fits
of another one. The merit of this transformation is that it enable us the use
of rats data as monkeys data simply by rescaling the PaCO2 values and the CBF
data. This transformation makes possible the use of experimental animal data
instead of human ones.
