Table 1.
Effects of zidovudine on soleus muscle histology, serum parameters, mtDNA, mitochondrial function, and muscle fiber-type characteristics
| Complete soleus muscle | Control (n = 10) | Zidovudine (n = 10) | P value | |||
|---|---|---|---|---|---|---|
| Soleus muscle fiber diameter (median μm) | 58.3 (IQR 54.2, 62.3) | 41.1 (IQR 37.5, 47.1) | <0.001 | |||
| Serum creatine kinase (U/L) | 724 ± 480 | 548 ± 257 | 0.3 | |||
| Serum creatinine (mg/L) | 3.6 ± 0.34 | 3.1 ± 0.11 | <0.001 | |||
| Serum glucose (mg/L) | 1,760 ± 100 | 1,680 ± 220 | 0.055 | |||
| Serum resting lactate (mM) | 4.5 ± 1.8 | 5.0 ± 1.6 | 0.9 | |||
| Serum alanine aminotransferase (U/L) | 66 ± 8 | 56 ± 7 | 0.1 | |||
| Serum aspartate aminotransferase (U/L) | 125 ± 35 | 101 ± 13 | 0.09 | |||
| mtDNA copy number (mean copies/myonucleus) | 559 ± 46 | 399 ± 78 | <0.001 | |||
| NADH DH (μmoles min-1 g muscle protein-1 ) | 684 ± 254 | 474 ± 236 | 0.042 | |||
| COX (μmoles min-1 g muscle protein-1 ) | 28 ± 8 | 18 ± 9 | 0.026 | |||
| SDH (μmoles min-1 g muscle protein-1 ) | 36 ± 6 | 35 ± 10 | 0.7 | |||
| NADH DH/SDH-ratio (% of control mean) | 100 ± 28 | 72 ± 20 | 0.027 | |||
| COX/SDH-ratio (% of control mean) | 100 ± 27 | 67 ± 26 | 0.016 | |||
| Single-fiber soleus muscle | Control | Zidovudine | p-value | |||
| Fiber type | Fast | Slow | Fast | Slow | Fast | Slow |
| Fiber-type proportion (% of all fibers) | 5.2 ± 3.0 | 94.8 ± 3.0 | 13.3 ± 5.1 | 86.7 ± 5.1 | <0.001 | <0.001 |
| Fiber diameter (mean μm) | 54.8 ± 5.8 | 65.5 ± 10.6 | 37.3 ± 9.3 | 51.8 ± 6.2 | <0.001 | 0.006 |
| mtDNA copy number (mean copies/myonucleus) | 617 ± 91 | 683 ± 94 | 384 ± 91 | 206 ± 97 | <0.001 | <0.001 |
Values represent group means (±SD); soleus muscle-fiber diameter values are given as median with interquartile range.