Endotoxin-induced changes in nitrogen metabolism.

Intraperitoneal administration of a sublethal dose of E. coli endotoxin to fasted rats produced within 12 hrs a rise in plasma ammonia, urea, glutamine, glutamate and aspartate as compared to controls. At this time, hepatic ureagenesis also increased as did the levels of glutamate, glutamine, aspartate, alanine and asparagine. However, liver glucose and ketone levels were unchanged. Hepatic [ATP]/[ADP] ratios declined in endotoxin-treated animals and there was an oxidation of mitochondrial pyridine nucleotides and a reduction of cytosolic pyridine nucleotides. The results suggest that impairment of nitrogen metabolism is an early effect of endotoxemia.