<正> Male mice were subjected to 6 Gy total body irradiation

20% TBSAfull-thickness burns

or combined radiation-burn injury and lipid peroxides（LPO）

vita-min E

sulfhydryl group

respiratory control ratio（RCR）

ADP/O ratio

and cytochromeoxidase activity of the liver mitochondria were determined in the first 9 d postinjury.Theresults are as follows:（1）LPO level increased in the early postinjury stage after combinedradiation-burn injury

on the 5th-7th day after irradiation and on the 7th day postburn.（2）Vitamin E level decreased significantly in the two groups of radiation and burn inju-ries but showed no significant decrease after combined injury.（3）The sulfhydryl groupshowed a tendency to increase in all the 3 groups.（4）The activity of cytochrome oxidaseincreased significantly on the 7th day after radiation but decreased considerably in theburn and combined injury groups.（5）RCR and ADP/O ratio decreased more significantlyin the combined injury group than in either the radiation group or the burn group.These facts suggest that the respiratory dysfunction of the liver mitochondria results mostprobably from the damage on the mitochondrial membrane due to lipid peroxidation.