Activities of enzymes of ketone body metabolism in liver and muscle tissues of suckling rabbits.

The concentration of ketone bodies in blood of suckling rabbits during the first 6 days following birth was higher than that found in the adult. In the liver the activities of the enzymes of ketone body synthesis were higher than in the adult during the same period. In the heart and leg muscle the activities of the enzymes of ketone body utilization were lower than those found in the adult. It is suggested that the capacity of the muscles of the developing rabbit to utilize ketone bodies is not greater than that of the adult and ketone bodies produced by the liver could contribute as fuel for oxidation and/or synthesis to the brain of the newborn rabbit.