Comparative study of leucine on digestive enzyme secretion, ISR and mTOR pathway in cattle and porcine pancreas in vitro

Abstract

ABSTRACT This experiment is to investigate whether interspecies differences exist in the effects of leucine (Leu) on digestive enzyme secretion in pancreatic tissues through in vitro. Five healthy Simmental cattle and Duroc × Landrace × Yorkshire growing-finishing pigs were selected, and pancreatic tissues were taken for culture after slaughter. Leu levels of 0, 2.62, 5.24, 10.48 mg/mL. Leu levels of 0, 5.24 mg/mL were selected to determine the expression of mRNA and proteins in the signaling pathways. The results showed that Leu increased the activity of digestive enzyme in cattle and pig, and there was an interaction was found on trypsin and chymotrypsin (P < 0.05). Leu had a significant effect on the mRNA (PKB, S6K1, 4E-BP1 and ATF4) and protein expression (PKB and 4E-BP1) and the phosphorylation (PKB, S6K1 and ATF4) levels (P < 0.05). Animal species had significant effects on the mRNA (PKB, S6K1 and ATF4) and protein (S6K1 and 4E-BP1) expression, and the phosphorylation (4E-BP1) levels (P < 0.05). There was an interaction between animal species and Leu on the expression of protein (PKB and S6K1) (P < 0.05). In summary, interspecies differences exist in the regulation of Leu on digestive enzyme secretion in pancreatic tissues in vitro of different animals.