CKD mice had an upregulated expression of MMP-9 mRNA compared to the non-CKD mice (2.789 ± 0.22 vs. 1.53 ± 0.54, p = 0.038), and it was attenuated by AST-120 in the CKD mice fed with AST-120 (1.11 ± 0.22 vs. 2.789 ± 0.22, p < 0.01). This evidence concerns the gene MMP9 and chronic kidney disease.