Rôle des polyamines dans l'agression

Influence of diet with or without amino acids on polyamine excretion in multiple trauma victims

Elevated levels of urinary polyamines (PA) in severely injured trauma patients are further enhanced by total parenteral nutrition (TPN) that contains both glucose and amino acids (AAs). Since TPN solutions contain arginine, the AA precursor of PA, it is not certain whether the increased urinary PA are due to this substrate. Nutritional factors can evidently modify PA metabolism. We measured the daily excretion of the PA, putrescine (PU) and spermidine (SD) in 18 multiply injured (injury severity score [ISS], 32 +/- 2), hypermetabolic (resting energy expenditure [REE]/basal energy expenditure [BEE], 1.41 +/- 0.06), and highly catabolic (daily N loss, 17.2 +/- 1.8 g N/d) acute trauma patients for 5 days in the early flow phase of injury. The patients were fed only maintenance fluids without calories or nitrogen for the first day 60 to 72 hours after injury, and then were randomized to receive glucose alone ([GLUC] 4.1 mg/kg/min, 80% measured REE, n = 8) or the same amount of glucose with AAs (TPN, 275 mg N/kg/d, n = 10) for the following 4 days. There was no significant difference in the enhanced daily PA excretion either in the free or acetylated form between the two dietary regimens. The addition of AAs in the TPN mixture did not seem to further stimulate PA metabolism in the trauma patients. The source of the nutrient content of the diet appears to be important for enhancing total PA excretion in critically ill patients.