Effect of dietary carbohydrate and chlortetracycline on growth and excretion of phenols in rats fed extra tyrosine

Abstract

1. 1. The effects on growth rate and the excretion of phenols, resulting from addition of increasing amounts of tyrosine to complete diets based on either lactose, sucrose, or sucrose plus chlortetracycline, were studied. 2. 2. At the 10% level of addition, only the lactose-fed rats gained weight. This gain in weight was correlated with a lower excretion of volatile phenols. 3. 3. Adaptation to increased tyrosine intake, indicated by a decrease in urinary phenol excretion, was correlated with an increase in the growth rate. 4. 4. p-Hydroxyphenylpyruvic acid constituted 35% and phenolic acids 80% of the total urinary phenol excretion, while only small amounts of homogentisic acid were excreted. 5. 5. Tyramine and p-hydroxyphenylpyruvic acid were isolated from the urine of rats fed 10% tyrosine.