L-tryptophan alleviates fatty liver and modifies hepatic microsomal mixed function oxidase in laying hens.

Abstract 1. 1. Three experiments were conducted to study the effect of dietary l -tryptophan supplementation (250–1000 ppm) on lipid accumulation, an occurrence of hemorrhages and microsomal mixed function oxidase in the liver of laying hens. 2. 2. Dietary l -tryptophan supplementation resulted in significant decreases in hepatic lipids, in particular triglyceride, and occurrence of hemorrhage in laying hens. 3. 3. Hepatic lipid accumulation by estrogen injection in starved-refed growing chicks decreased as dietary tryptophan content increased. 4. 4. Supplementation of l -tryptophan at 1000 mg/kg diet enhanced alanine aminotransferase activity in the hepatic tissue and at 500 mg/kg diet, increased cytochrome b5, a component of the mixed function oxidase, in the hepatic microsomes. 5. 5. These results demonstrate that l -tryptophan alleviates fatty liver in laying hens and modifies microsomal mixed function oxidase in the liver.