High doses of prednisolone increase protein breakdown in human muscle, leading to a negative nitrogen balance. This study looked at how 60 mg/day of prednisolone affects protein synthesis and degradation in skeletal muscle. After 3 days of treatment, there was a significant increase in protein degradation, with no clear effect on protein synthesis. The researchers found higher levels of certain amino acids in the blood and increased release of amino acids from the leg. The capacity for protein synthesis may have decreased, as shown by a reduction in polyribosomes. Overall, the findings suggest that high doses of prednisolone accelerate protein breakdown in muscle, but the exact mechanisms behind this process need further investigation.