DOES URINARY TAURINE REFLECT CHANGES IN PROTEIN-METABOLISM - A STUDY WITH CYCLOHEXIMIDE IN RATS

We have previously reported on the changes in urinary taurine levels i n rats following treatment with some hepatotoxic agents and compounds reported to affect protein synthesis. This study follows the time cour se of the elevation of urinary taurine after treatment of rats with cy cloheximide which was maximal 8-12 h after dosing and was dose related . [H-3]-Leucine incorporation into proteins was used as an indicator o f protein synthesis. There was a significant reduction in [H-3] leucin e incorporation into acid precipitable proteins 8 h but not 24 h after dosing. The reduction in incorporation was negatively correlated with the raised levels of both serum and urinary taurine 8 h after dosing. Liver glutathione was raised both 8 and 24 h after dosing rats and li ver taurine was significantly reduced at 8 h. It is suggested that mea suring urinary taurine in collections made continuously might provide a simple, non-invasive biomarker for monitoring the effects of xenobio tics or other external stimuli on the status of protein synthesis.