Effects of hypothermia on energy metabolism of metabolically loaded liver.

The effects of hypothermia on adenine nucleotide level, mitochondrial metabolism and redox state of the remnant liver were studied in 25, 50, 70 and 93% hepatectomized rabbits. In 25% of the hepatectomized rabbits, energy charge levels and mitochondrial phosphorylative activities remained unchanged, while in 50 and 70% hepatectomized rabbits, the energy charge levels decreased maximally at 24 hours after hepatectomy with a concomitant rise of mitochondrial phosphorylative activity. In 93% hepatectomized rabbits, the energy charge levels decreased rapidly without enhancement in mitochondrial phosphorylative activity and these rabbits died within 12 hours after hepatectomy. Body cooling significantly increased the energy charge of the remnant liver with further enhancement in mitochondrial phosphorylative activity in 25, 50 and 70% hepatectomized rabbits, but did not increase the energy charge in 93% hepatectomized rabbits. On the other hand, during body rewarming, the energy charge levels of the remnant liver decreased. More than 60% of 70% hepatectomized rabbits died during body rewarming, while all of 50% or less hepatectomized rabbits remained alive. Thus, body cooling may provide remarkable protection for the remnant liver from an energy crisis under the condition that compensatory mitochondrial enhancements are present.