Post-exercise changes in muscle glycogen content and blood metabolites in the dogs treated with triiodothyronine.

Post-exercise changes in muscle glycogen content and blood metabolites in the dogs treated with triiodothyronine. Acta Physiol. Pol., 1979, 30 (2) : 241--252. Prolonged T3-treatment markedly affected muscle glycogen content which was significantly lower than in controls both under resting conditions and after prolonged exercise. The post-exercise rate of the muscle glycogen resynthesis was inhibited in comparison with controls. Glucose (about 35 g per animal) infused to these dogs after cessation of exercise was able to bring about the rate of glycogen resynthesis to control values, but only during the first few hours of the recovery period. The present investigations confirmed that an excess of thyroid hormones elevates the lipolytic and lactacidemic responses to physical effort, but the pattern of the post-exercise changes in blood FAA and LA levels was similar in both groups. No differences between the control and T3-treated animals were found in the levels of blood catecholamines and insulin before, during and after exercise. Blood glucose level was significantly higher in T3-treated dogs at rest and markedly lower at the end of exercise in comparison with controls. The pattern of changes in BG level during the post-exercise period was similar in both animal groups.