Ontogenetic study of the effects of energetic nutrients on amino acid metabolism of rat cerebral cortex

We studied the effect of various energetic nutrients on metabolism of l-[U-C-14]leucine and [1-C-14]glycine in cerebral cortex of rats at different ages. At gestational age, glucose and lactate stimulated protein synthesis from l-[U-C-14]leucine and [1-C-14]glycine and from l-[U-C-14]leucine, respectively; glucose, beta-OH-butyrate and lactate stimulated lipid synthesis from l-[U-C-14]leucine. At 10 days of age, glucose, mannose, and fructose stimulated protein synthesis, and glucose and mannose stimulated oxidation to CO2 as well as lipid synthesis from l-[U-C-14]leucine. In adult rats, glucose, mannose, and fructose stimulated protein synthesis from l-[U-C-14]leucine and [1-C-14]glycine; glutamine also markedly decreased the oxidation of l-[U-C-14]leucine and [1-C-14]glycine in 10-day-old and adult rats.