Possible Interaction: Thyroxine and Tyrosine

“ Thyroxine , in further contrast to adrenal corticosteroids, produces elevations of the plasma level of tyrosine , and thyroidec-tomy decreases the concentration of tyrosine in plasma (13, 14).”

“ Thyroxine and analogues inhibit rat liver aminoacyl-tRNA synthetase activity for phenylalanine and tyrosine.”

“Summary Addition of thiouracil to a high tyrosine diet alleviated signs of tyrosine toxicity in the rat, whereas, daily injections of thyroxine aggravated them.”

“Measui'ements of 14C-tyrosine disappearance from plasma demonstrated that treatment with thyroxine increased the fractional turnover rate of tyrosine.”

“ L-Thyroxine treatment for only 1–3 days increased plasma tyrosine levels, but hepatic tyrosine transaminase activity wa...”

“ L-tyrosine contributed to another vital rise in dose-dependence than control, in bodyweight, GSI, and testosterone, T3, and T4.”

“At the same time, investigations were extended in vitro to show that the overall oxidations of tyrosine and of p-hydroxyphenylpyruvate were inhibited by thyroxine , and that tyrosine transaminase was more sensitive to the in vitro action of the hormone than was p-hydroxyphenylpyruvate oxidation.”