EFFECT OF SEPSIS ON BRAIN ENERGY-METABOLISM IN NORMOXIC AND HYPOXIC RATS

Neurological abnormalities including agitation, confusion, disorientat ion, lethargy, and obtundation are early characteristic findings in pa tients with sepsis. The etiology of the changes in mental status that occur during severe infection is unknown. We investigated the effects of sepsis on intermediary metabolism and bioenergetics in the brain du ring normoxia and moderate hypoxia (8% inspired O2 concentration) in r ats 36-42 hr following cecal ligation and perforation. The rats were a nesthetized with halothane, and brains frozen using the funnel-freezin g technique. Perchloric acid extracts of brains were analyzed with flu orometric enzymatic methods and P-31 nuclear magnetic resonance spectr oscopy. There was no impairment in bioenergetics or intermediary metab olism in septic brain, and sepsis did not compromise the ability of th e brain to maintain high-energy phosphates during hypoxia. Hypoxia did cause the brain lactate-to-pyruvate ratio to increase equivalently in both septic and control rats from approximately 9:1 to 20:1 (P < 0.00 1). We conclude that the neurologic changes which are characteristic o f sepsis are unlikely to be due to alterations in cellular energy stor es or intermediately metabolism. In addition, there is no evidence tha t sepsis results in brain cellular hypoxia. (C) 1993 Wiley-Liss, Inc.