Figure 1.
Allopurinol prevents soleus muscle atrophy after 14 days of hindlimb unloading in rats.
(A) The reticulin staining (Original magnification, 4×) shows a significant decrease in the soleus muscle cross-sectional area after hindlimb unloading. Allopurinol partially prevents it (Scale bar, 1 mm). (B) Quantitative analyses were used to confirm histological findings, by comparing the cross-sectional area of the different groups: control rats with water (CW) (n = 3), control rats with allopurinol (CA) (n = 3), unloading rats with water (UW) (n = 3) and unloading rats with allopurinol (UA) (n = 3). (C) Soleus muscle to body mass ratio. Values are mean (±SD) in CW (n = 9), CA (n = 9), UW (n = 7), and UA (n = 7). (D) Western blot and densitometric analysis of slow skeletal muscle myosin heavy chain in CW (n = 3), CA (n = 3), UW (n = 3), and UA (n = 3). A two-factor ANOVA and post hoc Bonferroni's comparisons were used to identify significant differences.
Figure 2.
Hindlimb unloading activates plasma and soleus muscle XO. Prevention by allopurinol.
Mean (±SD) results of XO activity in plasma (A) and soleus (B) of control with water (CW) (n = 9), control with allopurinol (CA) (n = 9), unloaded with water (UW) (n = 7) and unloaded with allopurinol (UA) (n = 7) rats. A two-factor ANOVA and post hoc Bonferroni's comparisons were used to identify significant differences.
Figure 3.
Effect of unloading and allopurinol treatment on soleus muscle and plasma protein carbonylation.
Mean (±SD) results of soleus muscle carbonylated proteins (A) of control with water (CW) (n = 9), control with allopurinol (CA) (n = 9), unloaded with water (UW) (n = 7) and unloaded with allopurinol (UA) (n = 7) rats. Figure B represents carbonylation of low-molecular weight protein (less than 50 kDa) in plasma of the same animals. A two-factor ANOVA and post hoc Bonferroni's comparisons were used to identify significant differences.
Figure 4.
Effect of unloading and allopurinol treatment on the protein levels of soleus muscle antioxidant enzymes.
Mean (±SD) results of CuZnSOD (A) and Catalase (B) protein levels in soleus muscle of control with water (CW) (n = 9), control with allopurinol (CA) (n = 9), unloaded with water (UW) (n = 7) and unloaded with allopurinol (UA) (n = 7) rats. A two-factor ANOVA and post hoc Bonferroni's comparisons were used to identify significant differences.
Figure 5.
Effect of unloading and allopurinol treatment on the activation of p38 MAPK.
Mean (±SD) results of cytosolic p38 MAPK in soleus muscle of control with water (CW) (n = 9), control with allopurinol (CA) (n = 9), unloaded with water (UW) (n = 7) and unloaded with allopurinol (UA) (n = 7) rats. Activation levels were expressed as the ratio between phosphorylated and total protein content. A two-factor ANOVA and post hoc Bonferroni's comparisons were used to identify significant differences.
Figure 6.
Effect of unloading and allopurinol treatment on the MAFbx levels in soleus muscle.
Mean (±SD) results of MAFbx mRNA levels in soleus muscle of control with water (CW) (n = 9), control with allopurinol (CA) (n = 9), unloaded with water (UW) (n = 7) and unloaded with allopurinol (UA) (n = 7) rats. A two-factor ANOVA and post hoc Bonferroni's comparisons were used to identify significant differences.
Figure 7.
Allopurinol prevents the loss of muscle mass during hindlimb unloading via inhibition of p38 MAPK and the E3 ubiquitin ligase Atrogin1/MAFbx.
Table 1.
Primer sequences used for real-time PCR.