AGE-RELATED ALTERATIONS OF THE BLOOD-BRAIN-BARRIER (BBB) PERMEABILITYTO PROTEIN MOLECULES OF DIFFERENT SIZE

Transfer processes of differently sized protein molecules across the b lood-brain-barrier (bbb) were studied in ''normal'', respectively, dis eased elderly humans. Lumbar CSF/serum ratio of albumin contents incre ased significantly with age in a control group, but it was diminished in patients suffering from inflammatory or non-inflammatory diseases. Ratio of alpha2-macroglobulin contents increased with age, especially in the diseased elderly. Concentration ratios of lysozyme, orosomucoid , lactoferrin, IgG, IgA and IgM decreased with age in a control group and especially decreased in a patient group. The data are discussed wi th respect to two different transfer processes which appeared to be al tered in age and/or disease processes.