LOW MOLECULAR WEIGHT ORGANIC ACIDS IN THE URINE OF THE NEWBORN

Abstract

The urinary excretion of 7 selected low molecular weight organic acids in normal neonates was measured by gas chromatography. First, and third to fourth day of life excretion of the following compounds was significantly unchanged: 3-OH-butyric acid (< 13 .mu.mol/mmol creatinine), succinic acid (approximately 43 .mu.mol/mmol creatinine), adipic acid (approximately 12 .mu.mol/mmol creatinine), 2-OH-glutaric acid (approximately 23 .mu.mol/mmol creatinine), 3-OH-3-Me-glutaric acid (approximately 25 .mu.mol/mmol creatinine) and citric acid (approximately 115 .mu.mol/mmol creatinine). The excretion of 4-OH-phenyl-acetic acid increased during the first 4 days of life (from < 8 .mu.mol/mmol creatinine to approximately 20 .mu.mol/mmol creatinine). Urinary organic acid excretion in the neonate, which is clearly different from the adult urinary pattern, is apparently a reflection of the specific neonatal metabolic situation, including a high fatty acid utilization and a low protein catabolism.