Glucose Uptake in Potassium‐Depolarized Mammalian Muscle

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Abstract
Experiments were performed on perfused cat hind limbs to study whether the uptake of glucose by striated muscle is linked with active transport of ions. The glucose uptake in the control periods was 1.4 μmole/100 g/min. Elevation of the plasma potassium concentration to 25–40 meq/l led to an average glucose uptake of 3.0 μmoles/100 g/min. Addition of strophanthin to a final concentration of 10‐5M strongly depressed glucose uptake, the average value being 0.3 μmole/100 g/min. The oxygen consumption in the strophanthin experiments fell from 7.3 μmoles/100 g/min to 6.9 μmoles/100 g/min. A Na/O‐ratio of 5 was calculated for mammalian muscle. Substitution with potassium‐rich blood after addition of strophanthin eliminated the strophanthin effect on glucose uptake. It is proposed that the mechanism for carrier‐mediated glucose uptake in mammalian muscle may be connected with the mechanism for active transport of either sodium or potassium.