Increased levels of alanine in serum after fasting is primarily due to:
Ans. a. Met loss of muscle protein due to increased breakdown (Ref: Ganong 24/e p21)Increased levels of alanine in serum after fasting are primarily due to net loss of muscle protein due to increased breakdown."The quantity of carbohydrate normally stored in the entire body can supply the energy required for body functions for 10-12 hours. Therefore, except for the first few hours of starvation, the major effects are progressive depletion of tissue fat and protein. Fat depletion is steady and continues unabated until most of the fat stores in the body are gone. Proteins undergo three phases of depletion-rapid depletion of mobilizable proteins at first, then greatly slowed depletion (during this time increased fat breakdown leads to a state of ketosis), and finally, rapid depletion again shortly before death. The major aim of protein catabolism during a state of starvation is to provide the glucogenic amino acids (especially alanine and glutamine) that serve as substrates for gluconeogenesis in the liver."
Net loss of muscle protein due to increased breakdown
Leakage from cells due to membrane damage
Renal dysfunction
Decreased rate of gluconeogenesis
Amino Acid Metabolism