Triiodothyronine (T3) increases mitochondrial respiration and promotes, in rodents, the uncoupling between oxygen consumption and ATP synthesis. The T3 effect is mediated partly through transcriptional control of genes encoding mitochondrial proteins. Here, we determined the effect of T3 on mRNA levels of uncoupling proteins (UCP) and proteins involved in the biogenesis of the respiratory chain in human skeletal muscle and on UCP2 mRNA expression in adipose tissue.
“T3 is also known to stimulate fatty acid oxidation. The decrease in respiratory quotient observed in our study suggests that T3 treatment induced an increase in fatty acid oxidation.”