Inhibition of succinate oxidation and K+ transport in mitochondria during hibernation.

Respiration of liver mitochondria of ground squirrels changes with physiological state. The inhibition of respiration at the level of dehydrogenases occurs during hibernation which is spontaneously removed during arousal. The main mechanism causing a decrease in respiration during hibernation seems to be the inhibition of succinate oxidation, induced by oxaloacetic acid. This is evidenced by the removal of the inhibition by glutamic and isocitric acids. A close correlation between the changes of K+ transport in mitochondria and of the physiological state of hibernator is observed. During hibernation the K+ transport rate decreases 3 times and during arousal it increases 1.5-fold in comparison with the active animals. The K+ content in mitochondria of hibernating and active ground squirrels is the same, whereas during arousal it increases 2-fold.