Influences of Taurine Deficiency on Bile Acids of the Bile in the Cat Model.

Taurine content in the body is maintained by both biosynthesis from sulfur-contained amino acids in the liver and ingestion from usual foods, mainly seafoods and meat. Contrary to the rodents, the maintenance of taurine content in the body depends on the oral taurine ingestion in cats as well as humans because of the low ability of the biosynthesis. Therefore, insufficient of dietary taurine intake increases the risks of various diseases such as blind and expanded cardiomyopathy in the cats. One of the most established physiological roles of taurine is the conjugation with bile acid in the liver. In addition, taurine has effect to increase the expression and activity of bile acid synthesis rate-limiting enzyme CYP7A1. Present study purposed to evaluate the influence of taurine deficiency on bile acids in the cats fed taurine-lacking diet. Adult cats were fed the soybean protein-based diet with 0.15% taurine or without taurine for 30 weeks. Taurine concentration in serum and liver was undetectable, and bile acids in the bile were significantly decreased in the taurine-deficient cats. Taurine-conjugated bile acids in the bile were significantly decreased, and instead, unconjugated bile acids were significantly increased in the taurine-deficient cats. Present results suggested that the taurine may play an important role in the synthesis of bile acids in the liver.