Protein synthesis in hyper functioning human thyroid tissue

Abstract

The rate of protein synthesis was examined it? vitro in thyroid tissue slices. The material was obtained from euthyroid patients operated on for hyperparathyroidism and from hyperthyroid patients with Graves' disease pre-operatively treated with propranolol alone. The rate of protein synthesis was calculated from the incorporation of [³H]leucine radioactivity in the soluble thyroid proteins (mainly the colloid proteins), the amount of soluble proteins per mg tissue and amount of DNA. Based on these figures it was observed that the rate of protein synthesis was 3.2 times higher in the hyper functioning thyroid tissue than in the normal tissue. A significant correlation was observed between this activity factor and the serum concentration of thyroxine. It is concluded that the increased hormone formation in hyperthyroid Graves' disease at least partly depends on an increased rate of protein synthesis in the follicular epithelium. This could be due to stimulation by thyroid immuno globulins, but other pathogenesis mechanisms may be responsible.

Key Words:

• hyperthyroid
• toxic goiter
• thyroid hormone formation
• protein synthesis