THE EARLY PATTERN OF CONJUGATED DIENES IN LIVER AND LUNG AFTER ENDOTOXIN EXPOSURE

If lipid peroxidation (LP) contributes to organ dysfunction in sepsis rather than simply reflecting established injury, it should occur soon after the onset of the septic insult, and it may not progress uniform ly in all organs. We assessed whether LP occurs within 90 min after on set of continuous intravenous endotoxin (E. coil 055:B5) infusion in r ats, using second-derivative spectroscopy to semiquantitatively assess conjugated dienes (CD) in lung, liver, and plasma phospholipids. Meas urements were also made after 90-min infusions with saline or 1 mM H2O 2. Both the quantity and spectrophotometric patterns of CD differed be tween the three groups. Compared with saline controls, lung lipid CD i ncreased after both H2O2 and endotoxin. Venous plasma CD were elevated only after H2O2, while arterial plasma and liver lipid CD were not di fferent between the three groups. Exhaled ethane (an indicator of pero xidation of omega-3 fatty acids) did not differ between groups. Wet-to -dry lung weights were significantly increased after endotoxin compare d with that after saline controls. Our results indicate that tissue-sp ecific LP occurs within 90 min of endotoxin or H2O2 intravenous infusi on.