Figure 6 Effect of pioglitazone (PGZ) on the cleaved and glycoforms of matrix metalloproteinase 13 (MMP‐13) in the liver of carbon tetrachloride (CCl₄) rats. Mean optical density of the glycosylated inactive form of MMP‐13 and the cleaved form of MMP‐13. Separation by electrophoresis of total liver homogenate in non‐denaturing conditions resolved the glycosylated form at 65–70 kDa and the cleaved MMP‐13 at 45–50 kDa (see methods). Data are mean for n = 5 per group, in duplicate, with 100% arbitrarily attributed to the sum of the glycosylated and cleaved forms of MMP‐13 in control livers. ***p<0.001 compared with control livers; †p<0.05 compared with five week CCl₄ livers under similar conditions. There were no significant differences between values obtained in 9 wk CCl₄ rats, treated or not with PGZ.