The effect of ageing on in vitro fidelity of translation in mouse liver.

In a polyuridylic acid (poly(U)) stimulated in vitro assay, there is an age-related reduction in polyphenylalanine synthesis with mouse liver microsomes. As measured by the incorporation of leucine under the same conditions, old microsomes make fewer errors in translation than do young ones. Old microsomes have a higher requirement for Mg2+ than young for the optimal synthesis on both acids, suggesting an age-related deterioration in poly(U) complexing ability.