REPLETION OF THE PLASMA POOL OF NUTRIENT TRANSPORT PROTEINS OCCURS ATDIFFERENT RATES DURING THE NUTRITIONAL REHABILITATION OF SEVERELY MALNOURISHED CHILDREN

Increased morbidity and mortality are associated with lower plasma pro tein concentrations in children with severe protein-energy malnutritio n. However, the kinetic changes responsible for repletion of the plasm a pools of nutrient transport proteins and the rapidity of their reple nishment in these children have not been determined. This study was un dertaken to determine whether an increased rate of synthesis is the me chanism responsible for repletion of the plasma retinol-binding protei n, transthyretin and high density lipoprotein-apolipoprotein A1 concen trations of children with severe malnutrition during nutritional rehab ilitation. The plasma concentrations and synthesis rates of retinol-bi nding protein, transthyretin and high density lipoprotein-apolipoprote in A1 were measured using a constant intragastric infusion of H-2(3)-l eucine in 22 children with severe protein-energy malnutrition, at simi lar to 2 d postadmission (study 1), similar to 8 d post-admission when infections were under control (study 2) and similar to 59 d postadmis sion at recovery (study 3), In study 1 the plasma concentrations and r ates of synthesis of all the proteins were lower compared with values at recovery, In study 2, retinol-binding protein and transthyretin con centrations and absolute synthesis rates increased to the recovered va lues seen in study 3, but the high density lipoprotein-apolipoprotein A1 concentration and synthesis rate remained significantly lower. Thes e results suggest that repletion of tile plasma pool of these three nu trient transport proteins occurs at different rates, through an increa se in the rate of synthesis.