Transport of malate and citrate into rat brain mitochondria under hypoxia and anesthesia.

Hypoxia and anesthesia inhibited penetration of malate and citrate into the brain mitochondria by 60% and 40%, respectively. Anesthetized animals exposed to low oxygen tension showed similar changes as those subjected to hypoxia without anesthesia. Recovery from anesthesia was rapid and the rates of citrate and malate uptake returned to the control values in approximately 60 min. In the case of hypoxia, days were required to restore the control values of citrate and malate uptake. Free fatty acids had no effect on the entry of malate and citrate into the mitochondria. However, changes in the levels of protein --SH groups were observed which may be responsible for the impaired transport of citrate and malate under hypoxic condition.