Effects of MMP-7 on BBB permeability as measured in vitro by TEER. Electrical potential between the extracellular side (ECS) and the luminal side as measured by TEER. After establishing the system, the TEER is typically ~650–700 Ohm/cm2 (black). The addition of MMP-7 to the luminal side resulted in a 15–20% drop in TEER during a 2 h halt in flow (green). This drop in TEER continued over the next 4 days, eventually resulting in a 40% reduction in TEER. The addition of recombinant MMP-7 to the ECS (red) side did not result in a near or longer term decrease in TEER, and slightly increase TEER over the course of the experiment. These two graphs were made from different apparatus, run simultaneously.
Buhler et al. BMC Neuroscience 2009 10:17 doi:10.1186/1471-2202-10-17