Figure 1.
Soleus muscle mass (grams) 7 days post either hormonal treatment (Dexa 7d; A) or hind limb immobilization (Imob 7d; B). Rats were supplemented with either HMB (Dexa 7d+HMB; A and Imob 7d+HMB; B) or Leucine (Dexa 7d+Leu; A and Imob 7d+Leu; B). a, p<0.05 vs control, b - p<0.05 vs. Imob. Bars represent mean+SD.
Figure 2.
Cross sectional area from fiber types I and II.
Soleus muscle fibers cross sectional area (CSA, µm2) of fiber types I and II 7 days post either dexamethasone treatment (A and B) or hind limb immobilization (C and D). a- p<0.05 vs. Control; b - p<0.05 vs. Imob. Bars represent Mean+S.D.
Figure 3.
Effect of HMB and leucine supplementation under single twitch and tetanic force during atrophic stimuli.
Single twitch force (in grams) and Tetanic peak force (in grams) in animals submitted to dexamethasone treatment or hind limb immobilization. White bars represent Mean±SD in Control group; black bars represent Mean±SD in Dexa, Dexa+HMB and Dexa+Leu groups; Striped bars represent Mean±SD in Imob, Imob+HMB and Imob+Leu groups. a- p<0.05 vs. Control; b - p<0.05 vs. Imob.
Figure 4.
Atrogenes and deubiquitinating enzymes gene expression during HMB or leucine supplementation per se.
Gene expression of Atrogin-1 (A), MuRF1 (B), UBP69 (C), UBP45 (D) and USP28 (E) during leucine (filled line -1, 4 and 6 days) or HMB (dashed line -1, 4 and 6 days) supplementation. Control is arbitrarily set to 1. Data are expressed as mean±S.D. (n=5 per group). a- p<0.05 vs. Control; b - p<0.05 vs. Leu.
Figure 5.
Effect of HMB and leucine supplementation under E3 ligases gene expression during atrophic stimuli.
Gene expression of Atrogin-1 (A and B) and MuRF1 (C and D) during either dexamethasone treatment (A and C) or hind limb immobilization (B and D). Control is arbitrarily set to 1. Data are expressed as mean±S.D. (n=5 per group). a- p<0.05 vs. Control; b - p<0.05 vs Dexa or Imob in respective time point; c - p<0.05 vs. Imob+HMB in respective time point.
Figure 6.
Effect of HMB and leucine supplementation under deubiquitinating enzymes gene expression during atrophic stimuli.
Gene expression of UBP69 (A and B), UBP45 (C and D) and USP28 (E and F) during either dexamethasone treatment (A, C and E) or hind limb immobilization (B, D and F). Control is arbitrarily set to 1. Data are expressed as mean±S.D. (n=5 per group). a- p<0.05 vs. Control; b - p<0.05 vs Dexa or Imob in respective time point; c - p<0.05 vs. Dexa+HMB or Imob+HMB in respective time point.
Figure 7.
Total ubiquitinated proteins levels.
Representative Western blot of ubiquitin-protein conjugates 3 days after dexamethasone treatment or hind limb immobilization, under HMB (Dexa+HMB and Imob+HMB, respectively) or leucine supplementation (Dexa+Leu and Imob+Leu, respectively). Each lane represents one of three independent experiments (n=3 per group).
Figure 8.
Effect of HMB and leucine under PI3K/AKT protein levels during atrophic stimuli.
Representative protein level of PI3K, AKT total, AKT phosphorilation residues at Thr308 and Ser473 and 4E-BP1, 3 days after dexamethasone administration or hind limb immobilization, under leucine (Dexa+Leu and Imob+Leu, respectively) or HMB (Dexa+HMB and Imob+HMB, respectively). Each pair of lanes represents a duplicate of each group (n=4 per group). Sarcomeric actin was used as loading control. The bars in B and C represent mean±S.D. a -p<0,05 vs. Control.