Changes of pyruvate dehydrogenase in rat brain with thyroid hormones

Thyroid hormone deficiency increased the activity of PDHa (active) in three regions of the rat brain with insignificant changes in the total form; a regional variation was also observed. Treatment of thyroidectomized rats with triiodothyronine restored the enzyme activity to almost control values after 60 days of thyroidectomy in all the three regions. Administration of T3 to control animals decreased the PDHa by 70% without affecting the total form. Results are discussed in relation with insulin sensitivity of various tissues.