Synthesis and degradation of chicken liver xanthine dehydrogenase during development.

Abstract

Abstract The rate of synthesis and degradation of xanthine dehydrogenase in 14-day-old chick embryos, 1-day-old and 8-day-old chicks was determined. When [ 14 C]arginine is used the rate constant for synthesis is low in the embryo, increases about 4-fold immediately upon hatching, and reaches a maximum by the eighth day after hatching. The rate constant when [ 14 C]valine is the substrate is 2.5 times greater in the 1-day-old chick than the value obtained with arginine. Degradation of xanthine dehydrogenase is low in the embryo, or the 1-day-old chick, but increases in the 8-day-old chick.