Changes in BBB permeability in Apo E−/−
mice exposed to mixed vehicle emissions. Changes in BBB permeability were assessed using the fluorescent tracer, sodium fluorescein (Na-F). Apo E−/− mice were exposed by inhalation to either (A) mixed vehicular engine exhaust (MVE: 100 μg PM/m3) (n = 6) or (B) filtered air (n = 6), and were injected i.p. with 100 μl of 2% Na-F –PBS 30 min prior to the end of their final exposure on day 30. Green fluorescence (arrows) in (midsagittal) sections of cerebral cortex at 4x (40× inset) indicates increased BBB permeability; blue fluorescence is DAPI nuclear stain. Scale bar = 500 μm. (C) Total fluorescence in (right) half of cerebrum, as measured by fluorometry. Data is expressed as amount of tracer per gram of tissue. *p < 0.050 compared to FA control.