Reverse zymographic analysis of TIMP levels in the mouse thoracic aortas. Mouse thoracic aortas from wild type control, mgR/mgR, and doxycycline-treated mgR/mgR mice harvested at 6 weeks of age (n=5 mice/group). Aortic proteins were separated by electrophoresis on a 12.5% SDS-PAGE containing 1.6% gelatin, 0.16 μg/ml MMP-2. A representative reverse zymogram shows the bands representing gelatin preserved by TIMP-1 and TIMP-2 (indicated by arrows). Band intensities were measured by densitometer. Relative expression of TIMP-1 and TIMP-2 in wild type control, mgR/mgR, and doxycycline-treated mgR/mgR mouse aortas was analyzed.