Research Paper Volume 1, Issue 9 pp 784—802

Figure 9. Effects of 3-NPA, an inhibitor of CII (succinic dehydrogenase) activity on the phosphorylation of the p38 MAPK catalytic site in fibroblasts from young (4-6 mos) and old (21-24 mos) wild-type and dwarf mice. (A) The bar graphs and western blot analyses below each bar graph show the phosphorylation levels of the p38 MAPK catalytic site amino acid residues (P-Thr¹⁸⁰/P-Tyr¹⁸²) in (A) young fibroblasts (4-6 mos) and (B) old wild-type and dwarf fibroblasts after treatment with 5 mM or 20 mM 3-NPA. The fibroblasts from young dwarf mice show an attenuated response to the 3-NPA-mediated phosphorylation of the catalytic site (n=3). Both young and old wild-type and dwarf fibroblast responses peak at 30 minutes. However, the recovery of the old wild-type cells is delayed. The fibroblasts from old dwarf mice also show resistance and rapid recovery to 3-NPA treatment similar to the response shown by the young dwarf fibroblasts. *represents p<0.05 between wild-type vs. dwarf.