Changes of essential amino acids in thyropathies.

Composition of free amino acids in serum of patients with thyrotoxicosis and hypothyroidism was studied by gas chromatography. In thyrotoxicosis the level of serum amino acids, especially the essential ones and several glucogenic amino acids, increased. The reverse was found to a lesser extent in hypothyroidism. Thyrotoxicosis exerted an increase and hypothyroidism a decrease in the value of the ratio of the sum of all essential amino acids versus the sum of all nonessential amino acids. The elevation of glucogenic amino acids in thyrotoxicosis is discussed with respect to hepatic function and amino acid mobilization and transport.