Effect of elevated dietary tryptophan on protein synthesis in rat liver.

This study investigated whether rats force-fed for three days an elevated (1%) tryptophan diet compared to a control (0.2% tryptophan) diet had changes in hepatic protein metabolism. Earlier, we showed that a single administration of L-tryptophan to fasted rats caused a rapid increase in hepatic protein synthesis. In the present study rats force-fed a high tryptophan diet for 3 days and killed the fourth morning had increased rats of hapatic protein synthesis, cytochrome P-450 and b5 activities, in vitro nuclear RNA release (cell sap and nuclear effects) and nuclear envelope nucleoside triphosphatases activity compared to animals force-fed the control diet. We noted little or no change in hapatic total polyribosomal aggregation patterns or plasma and hepatic free amino acid levels.