EFFECTS OF THYROID-HORMONES ON THYMOCYTE ENERGETICS

It has been demonstrated that on administration of thyroxine (T4) for 7 days at 200 mug per kg of mass, pyruvate being the substrate of oxidation, the rate of oxygen consumption increases by 46% alongside with uncoupling of oxidative phosphorylation (OP), as evidenced by the increased rate of respiration with oligomycin. mycin. Preincubation of thymocytes with triidothyronine (T3) (1 muM) for 15 min stimulates oxidation of pyruvate by 42% without any uncoupling of OP. Thyroidectomy brings about a decrease in the rate of respiration of thycomytes by 44% as related to the cells of falsely thyroidectomyzed animals without uncoupling of OP. Tehrefore, the energy metabolism of thymocytes is regulated by thyroid hormones the same way as hepatocyte metabolism.