Localization of microbial L-tyrosine degradation in the intestine of coprophagy-prevented rats.

Abstract

The urinary excretion of simple phenols was studied in coprophagy-prevented rats fed a casein-sucrose diet containing added L-tyrosine. After neomycin administered intracaecally the excretion of p-cresol and phenol was only 4% and 20%, respectively, of the amount in sham-operated controls. The excretion of phenols was reduced after prevention of coprophagy, but a similar reduction occurred in rats wearing sham-cups. In rats given 3H-L-tyrosine intragastrically or intracaecally through identical abdominal incisions, the recovery of radioactivity in the simple phenol fraction was 0.5 ± 0.1% and 34 ± 3%, respectively. These findings indicate that the large bowel is capable of absorbing simple phenols and that it is the most important site of microbial L-tyrosine degradation.