Insulin-mediated activation of glycogen synthase in isolated skeletal muscle: role of mitochondrial respiration.

Activation of glycogen synthase (GS) by insulin in isolated, aerated muscle was abolished when oxygen was replaced by nitrogen. Reoxygenation of the muscle after prior exposure to nitrogen restored the insulin effect. In the presence of cyanide (inhibitor of mitochondrial respiration) insulin did not activate GS. These data demonstrate that adequate mitochondrial respiration is required for insulin-mediated activation of GS.