Food deprivation exacerbates mitochondrial oxidative stress in rat liver exposed to ischemia-reperfusion injury

Mitochondria undergo oxidative damage during reperfusion of ischemic liver. Although nutritional status affects ischemia-reperfusion injury in the liv er, its effect on mitochondrial damage has not been evaluated. Thus, this s tudy was designed to determine whether starvation influences the oxidative balance in mitochondria isolated from livers exposed to warm ischemia-reper fusion. Fed and 18- and 36-h food-deprived rats underwent partial hepatic i schemia followed by reperfusion. Mitochondria were isolated before and afte r ischemia and during reperfusion. Serum alanine transaminase was measured to assess liver injury. The mitochondrial concentrations of malondialdehyde , protein carbonyls and glutathione were determined as indicators of oxidat ive injury. Cell ultrastructure was assessed by transmission electron micro scopy. Transaminase levels were greater in 18-h food-deprived than fed rats (after 120 min of reperfusion: 3872 +/- 400 vs. 1138 +/- 59 u/L, P < 0.01) . Mitochondrial glutathione was lower in food-deprived than fed rats before and after ischemia, and during reperfusion. Food deprivation also was asso ciated with significantly greater lipid and protein oxidative damage. Final ly, more ultrastructural damage was observed during reperfusion in mitochon dria from food-deprived rats. Prolonging the length of food deprivation to 36 h exacerbated significantly bath the mitochondrial oxidative injury and the release of serum transaminases in rats (after 120 min of reperfusion: 5 438 +/- 504 u/L, P < 0.01). Food deprivation was associated with greater mi tochondrial oxidative injury in rat livers exposed to warm ischemia-reperfu sion, and the extent of oxidative damage in mitochondria increased with the length of food deprivation.