A 63-year-old male with a history of congestive heart failur…

A 63-year-old male with a history of congestive heart failure was prescribed the drug digoxin, which improves heart function by inhibiting the Na+/K+ ATPase. Patients taking digoxin may experience toxicity due to effects of digoxin on tissues throughout the body. Which of the following blood test results would be most likely in a patient experiencing digoxin toxicity?

A study published in 2017 reported a correlation between low…

A study published in 2017 reported a correlation between low alanine aminotransferase (ALT) levels in muscle and age-related muscle loss (sarcopenia) in the elderly. ALT activity is required for alanine shuttle function. Accumulation of which of the following in muscle tissue best explains the development of sarcopenia in elderly individuals with low ALT levels?