Effect of undernutrition on metabolic compartmentation of glutamate and on the incorporation of [14C] leucine into protein in the developing rat brain.

The effect of undernutrition on the rate of protein synthesis and the development of metabolic compartmentation of glutamate in the brain was investigated by using [U -14 C] leucine as precursor. In the brain of normal rats the incorporation rate of [14C] leucine into protein was at a maximum during the 3rd week after birth, but in the undernourished animal this rate was markedly lower. The biochemical maturation of the brain, followed in terms of the age-dependent increase in the glutamine/glutamate specific radioactivity ratio, was severly retarded in the undernourished animals, mainly as a result of a marked depression in the conversion of leucine carbon into glutamine. However these biochemical effects of undernutrition were reversible: on rehabilitation from Day 21-35 the rate of conversion of leucine carbon, both into proteins and glutamate and glutamine, was restored to normal.