Relationship of Plasma-Free Amino Acids and Aminotransferase Expression in Nile Tilapia Oreochromis niloticus (Cichlidae)

Abstract

There is a relationship between concentrations of free amino acids in blood plasma in Nile tilapia and expression levels of hepatic enzymes involved in protein catabolism. It was established that expression levels of alanine aminotransferase and aspartate aminotransferase hepatic transcripts correlated with clearances of amino acids under deamination. Alanine aminotransferase activity had its maximum at the beginning of absorption, while aspartate aminotransferase had prolonged activity and mainly contributed to metabolism maintenance but did not determine amino acid catabolism rate.