Liver histology and serum transaminases in MaS-MMP-9−/− (white bars) and MaS-WT (black bars) mice. H&E staining (panel A) of MaS-MMP-9+/+ (a, c, e, g, i, and k) and MaS-MMP-9−/− (b, d, f, h, j, and l) livers evidence that MMP-9 deficiency resulted in a significant improvement of liver histological preservation at 6h (a-d), 24h (e-h) and 48h (i-l) post-IRI. sAST (panel B) and sALT (panel C) levels were significantly decreased in MaS-MMP-9−/− mice, when compared with controls. The percentage of hepatocellular necrosis (panel D) was decreased in the MaS-MMP-9−/− livers post-IRI. (n=4-6 mice/group *p<0.05).