Alanine metabolism in patients with chronic infection

Alanine matabolism was studied in surgical patients with chronic infection and non-infected control subjects by means of an intravenous infusion of alanine. Septic patients had low basal blood concentrations of alanine compared with control subjects but alanine half-life was similar in both groups. This suggests that low basal alanine concentration in the septic patients was due to decreased release from muscle rather than increased hepatic uptake. Alanine infusion in septic patients caused a fall in the blood concentration of ketone bodies which was initially raised. Similar increases in blood concentrations of glucose, lactate, pyruvate an insulin occurred in both septic and control patients after alanine infusion. Hyperketonaemia may limit muscle breakdown and alanine release in patients with chronic infection.