Abstract
Pituitary G-6-PDH activity was increased when pituitary weight is augmented by the use of a low iodine diet or treatment with methiocil for a few weeks. In contrast, pituitary enzyme activity was decreased by T4 treatment.
The increased enzyme activity may be due to the increased weight of pituitary as a result of prolonged elevation of TSH secretion. However, the augmentation of pituitary weight was less pronounced following treatment with methiocil or low iodine in comparison with the increase in thyroid weight. Therefore, the augmentation of total enzyme activity in the pituitary was less than that in the thyroid. This experiment showed that pituitary G-6-PDH activity is increased in the pituitary gland when a continuous increase in TSH secretion occurs.
