[Effect of experimental changes in thyroid function on oxidative metabolism and glutamate dehydrogenase activity in...

The oxidative metabolism and GDH activity has been studied in the following regions of the brain: frontal cortex, as tissue control, adenohypophysis, hypothalamus and limbic system in adult male rats subjected to alterations of the thyroid function due to excess (by hyperthyroidism with L-thyroxine and thyrotoxicosis with Tri-iodothyronine) or defect (chronic hypothyroidism by thyroidectomy, 131-I treatment and low iodine diet). A different influence of the H.T. was observed in these animals according to the areas studied and the experimental situation induced. All this seems to indicate an oxidative metabolic pattern peculiar to each area of the brain following H.T. administration. On the other hand, the decrease of the QO2 in chronic hypothyroidism in the majority of the areas studied is remarkable. In GDH results activity increased or decreased depending on the absence or presence of thyroid hormones.