Synthesis of threonine dehydratase in neonatal rat liver

Antiserum against rat threonine dehydratase has been raised in rabbits. The rate of incorporation of [3H]leucine into threonine dehydratase was found to increase dramatically after birth. Actinomycin D suppressed the rate of the synthesis of the enzyme in the postnatal rat liver, although the antibiotic was without effect on the incorporation of leucine into total cytosolic protein. The administration of dibutyryl-adenosine 3',5'-monophosphate to foetal rats in utero or postnatal rats resulted in a marked enhancement of the rates of synthesis of threonine dehydratase.