Fig. 2.

Western blot analysis of antioxidant enzyme protein expressions in the rats’ tongues of two age groups, namely 7 months (young group, n=8) and 22 months (old group, n=8). Protein (20 ug) lysates from tongue homogenates of young and old rats were resolved by SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel) and probed with Mn-SOD, Cu/Zn-SOD, CAT, and GPx antibodies as described in Materials and Methods. GAPDH was used as a loading control. Blots of (A) Mn-SOD, (B) Cu/Zn-SOD, (C) GPx, and (D) CAT were shown with quantification of the protein expression by normalizing each band signal to their corresponding GAPDH band. Results are expressed as median values. SOD, superoxide dismutase; GPx, glutathione peroxidase; CAT, catalase; GAPDH, glyceraldehyde-3-phosphate dehydrogenase. ^a)P<0.05. ^b)P<0.01 vs. the young group by the Mann-Whitney test.