Altered peripheral amino acid uptake in obstructive jaundice.

To characterize amino acid metabolism in obstructive jaundice, the amino acid uptake in tissues of bile duct-ligated (BDL) rats was determined. Fischer 344 rats underwent either bile duct ligation or sham laparotomy and were pair fed for 72 hr. Amino acid uptake was determined in peripheral skeletal muscle (quadriceps femoris, soleus, and rectus abdominis), liver, blood, and other tissues by accumulation of alpha-[14C]-aminoisobutyric acid following intracardiac injection. Although total hepatic amino acid uptake was unaltered in the BDL animals compared with the sham-operated controls, amino acid uptake in peripheral skeletal muscle was significantly decreased in all muscle groups studied in the BDL rats. The relative concentration (percentage dose per gram normalized to the animal mass) for quadriceps femoris was 0.16 +/- 0.02 for BDL and 0.32 +/- 0.04 for sham-operated rats, P less than 0.005. Muscle protein was lower in BDL animals when compared with sham-operated rats (P less than 0.05). Total trunk blood amino acid levels were not significantly different in the two groups; however, there was a decreased serum level of branched-chain amino acids in the BDL group, P less than 0.05. No differences in plasma glucose or serum insulin were found in the two groups; lactate levels were lower in the BDL group, and plasma triglyceride levels were three times higher in the BDL animals. These data suggest that obstructive jaundice in the rat is associated with organ-specific metabolic abnormalities consistent with impaired peripheral amino acid uptake.