Figure 7. Exogenous administration of UnAG in old WT mice attenuates age-related muscle decline. UnAG 100 μg/Kg was injected daily i.p. for 28 days to 18-month-old mice (N = 6). Age- and weight-matched controls were injected with saline (N =6). (A) Total body weight; (B) daily food intake; (C) change in epidydimal fat mass normalized to nose-to-anus length (NAL) and in (D) muscle mass normalized to the tibial length (TL). GAS: gastrocnemius, SOL: soleus, QUAD: quadriceps, TA: tibialis anterior, EDL: extensor digitorum longus. (E) Average score trend in hanging wire test and (F) average holding impulse. (G) Cross-sectional area (CSA) frequency distribution of myofibers in GAS. The shadowed areas of the graph represent the sections of statistically significant differences among curves. (H) IGF-1 (Igf1), (I) Atrogin-1 (Fbxo32), and (J) Cathepsin-L (Ctsl) expression in gastrocnemius determined by real-time RT-PCR. (K) Quantification of SDH staining in TA muscle presented as the percentage of SDH-positive area above the total muscle surface. Data in bar graph are presented as mean ± SEM. For box plots, the lower and up boundaries denote the 25th and the 75th percentile of each data set, respectively, the horizontal line represents the median, and the whiskers represent the min and max of values. *p<0.05 and **p<0.01 vs. saline-treated controls.