Variations in pyridine nucleotides in liver of fetal, newborn, and adult guinea pigs

¹ Physiological Department, Research Laboratories of the State Alcohol Monopoly, Helsinki, Finland

Concentrations of oxidized diphosphopyridine nucleotide (DPN) and oxidized triphosphopyridine nucleotide (TPN), reduced diphosphopyridine nucleotide (DPNH) and reduced triphosphopyridine nucleotide (TPNH) were determined enzymatically in fetal, newborn, and adult guinea pig liver. Acid-soluble nucleotides were determined by anion-exchange chromatography in fetal and adult guinea pig liver. The concentration of DPN shows a slight increase from a mean of 418.0 mµmoles/g liver in fetal liver to 533.3 mµmoles/g in the adult. DPNH is low in fetal liver, 26.0 mµmoles/g, increasing rapidly after birth to the adult value of 127.0 mµmoles/g. The concentration of TPN is low in both fetal and adult liver and could not be determined accurately. TPNH increases from 125.0 mµmoles/g in fetal liver to a mean of 185.0 mµmoles/g in adult liver. Anoxia increases the concentration of DPNH in both fetal and adult liver, whereas TPNH tends to decrease, especially in fetuses near term. No effect on DPN and TPN was found. The other acid-soluble nucleotides determined are present in fetal liver in a lower concentration than in the adult liver. Results are discussed in relation to the high fat content of the fetal liver.