The effect of ouabain on basal and thyroid hormone-stimulated muscle oxygen consumption

In vivo triiodothyronine treatment (T3) increased soleus muscle oxygen consumption (QO2) when measured in vitro. Ouabain significantly decreased T3-induced muscle QO2, but not basal muscle QO2. Ouabain-sensitive metabolic processes in muscle, which essentially represents Na-K-ATPase activity, accounted for approximately 85% of the increased energy utilization by muscles that was caused by T3 treatment.