Protein synthesis in central nervous tissue: studies on retina in vitro.

摘要: Rabbit retinas were maintained in vitro medium that resembled CSF but with leucine varied from 2 to 1000 microM. Both and threonine isotopically labelled. When the was 100-1000 microM, incorporated into protein at 2.03 +/- 0.04 (S.E.M.) mumol/g dry wt./h, a turnover per h of 0.55% retinal protein. Incorporation constant for least 7 h. It reduced 34% when other amino acids omitted 24% they increased 15 fold above physiological levels. microM constant, 14C-leucine incorporation fell 70% without significant change 3H-threonine incorporation, indicating fall intracellular specific activity leucine. The intracellular/extracellular concentration ratio labelled 4:1 23 markedly or 15:1 levels 6:1 Decarboxylation removed 1.5% free min and, concentrations, 7.7% rate incorporation. synthesis/breakdown, estimated changes essential medium, nearly unity. potential this preparation study CNS metabolism is discussed.