Synthesis of NAD and Catabolism of Nicotinic Acid in the Isolated Perfused Liver of Normal and X-irradiated Rat

SummaryThe synthesis of NAD and the formation of catabolites from nicotinic acid 14C was studied in isolated perfused liver from normal and x-irradiated rats. Large amounts of nicotinic acid and nicotinamide increase NAD content of perfused liver as they do in vivo. Synthesis of NAD is slightly diminished after irradiation, particularly under loading conditions whereas its catabolism is enhanced. Data for the rates of reactions are given for different pathways involved in NAD metabolism.