Lipitor, also known as atorvastatin, is a medication used to lower cholesterol levels in the blood and reduce the risk of heart disease and stroke [1]. According to Drug Patent Watch [1], Lipitor is a statin drug that works by inhibiting an enzyme called HMG-CoA reductase, which is involved in the production of cholesterol in the liver. By blocking this enzyme, Lipitor reduces the amount of cholesterol produced by the liver and increases the liver's ability to remove LDL cholesterol from the bloodstream.

The impact of Lipitor on protein metabolism has been studied in various research studies. A study published in the Journal of Lipid Research [3] investigated the effects of atorvastatin on protein metabolism in rats. The study found that atorvastatin treatment increased protein synthesis in the liver and muscle tissues of the rats. The authors suggested that this effect may be due to the activation of a protein called mTOR, which is involved in regulating protein synthesis.

Another study published in the Journal of Clinical Lipidology [2] examined the effects of atorvastatin on muscle metabolism in humans. The study found that atorvastatin treatment did not significantly affect muscle protein synthesis or breakdown in healthy individuals. However, the study did find that atorvastatin treatment improved muscle function and reduced muscle damage in individuals with muscle weakness.

In conclusion, while Lipitor is primarily used to lower cholesterol levels, it may also have some impact on protein metabolism. Studies suggest that atorvastatin treatment may increase protein synthesis in liver and muscle tissues, possibly through the activation of the mTOR pathway. However, the effects of atorvastatin on muscle protein metabolism in humans are not well understood and require further research.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5489069/
[3] https://pubmed.ncbi.nlm.nih.gov/15942117/