Comparative study of the proteinase inhibitor pattern in serum and cerebrospinal fluid.
After concentration the alpha 1-proteinase inhibitors (Pi) of cerebrospinal fluid (CSF) were separated by isoelectric focusing. The relative amounts of the different Pi components in the CSF were compared with those in the serum of the same donor. The Pi components were identified by crossed isoelectric focusing. Most of the serum Pi components could be detected in the CSF but their relative proportions in serum and CSF differed considerably. The typical serum Pi patterns observed for different phenotypes were not reflected in the CSF. In cases when CSF protein levels were abnormally high alterations of the CSF Pi pattern were observed, i.e. the proportions of at least some of the Pi components approached those in serum. It is concluded that CSF Pi components originate from the serum and that a highly selective blood-CSF barrier function results in a considerable alteration of the concentration pattern. It has been shown by crossed isoelectric focusing technique that at least two proteins acting as Pi in serum do not exert antiproteolytic activity in CSF. Consequently, in CSF these Pi components may have been chemically modified, resulting in an alteration of the acceptor sites but not of the isoelectric point of the inhibitor molecule.
D001798:Blood Proteins / Q000378:metabolism*; D006801:Humans; D007525:Isoelectric Focusing; D019965:Neurocognitive Disorders / Q000201:enzymology; D011480:Protease Inhibitors / Q000378:metabolism*; D014018:Tissue Distribution; D000515:alpha 1-Antitrypsin
D001798:Blood Proteins; D011480:Protease Inhibitors; D000515:alpha 1-Antitrypsin