Abstract
Prealbumin, was determined in serum, lumbar and ventricular cerebrospinal fluid (CSF) and compared with albumin and IgG. The measured concentrations of prealbumin in the CSF indicate that there are two sources of prealbumin: a minor fraction enters the CSF via the blood-cerebrospinal fluid (B-CSF) barrier like albumin, and the major fraction enters the CSF at the ventricles, probably during production of the CSF in the ventricles. The two fractions can be calculated from the CSF concentration of prealbumin, serum prealbumin and the concentration gradient (serum/CSF) of albumin. The B-CSF barrier-independent prealbumin can be used as an indicator of CSF circulation. This was proved by the investigation of several special cases.