AIIMS November 2011 – MCQ 198
Increased level of alanine in serum after fasting suggests?
A. Increased muscle breakdown
B. Reduced amino acid utilisation from gluconeogenesis
C. Break in continuity of plasma membrane resulting in leakage of amino acids
D. ?
Please contribute to the discussion by posting the answer with references and pointing out the errors in the question!
2 Comments
The recycling of peripheral lactate and pyruvate for hepatic gluconeogenesis is accomplished by the Cori cycle. Alanine within skeletal muscles can also be used as a precursor for hepatic gluconeogenesis. During starvation, such fatty acid provides fuel sources for basal hepatic enzymatic function.
Schwartz surgery-Metabolism during Fasting
Thus it seems that 2cnd choice is a valid answer.
On the same note though-
Precursors for hepatic gluconeogenesis include lactate, glycerol, and amino acids such as alanine and glutamine.Lactate production from skeletal muscle is insufficient to maintain systemic glucose needs during short-term fasting (simple starvation). Therefore, significant amounts of protein must be degraded daily (75 g/d for a 70-kg adult) to provide the amino acid substrate for hepatic gluconeogenesis. Proteolysis during starvation, which results primarily from decreased insulin and increased cortisol release, is associated with elevated urinary nitrogen excretion from the normal 7 to 10 g per day up to 30 g or more per day.54 Although proteolysis during starvation occurs mainly within skeletal muscles, protein degradation in solid organs also occurs.
Schwartz surgery-metabolism during fasting
THis shows that the 1 st choice is also partially correct. I hope the last choice is all of the above.