Hepatic cumulative net appearance of amino acids and related gene expression response to different protein diets in pigs

Abstract The liver is an important organ responsible for amino acids (AA) conversion, and catabolism. To investigate the metabolic characteristic of AA in liver, eighteen castrated male pigs (20±1 kg), implanted with arterial–portal–hepatic–mesenteric catheters, were fed three crude protein (CP) diets (14%, 17%, 20%) with six pigs per group. Blood was sampled for 7.5 h post-feeding. Hepatic tissue was sampled from additional fifteen pigs (three CP diets groups, 5 per group) on 3 h post-feeding. Portal vein plasma flow (PVPF), hepatic vein plasma flow (HVPF), hepatic cumulative net appearance and related gene expression were analyzed. There were no difference ( P >0.05) for PVPF and HVPF among the three CP diets. Compared with the 20% CP diet, the 14% CP diet increased ( P l -threonine 3-dehydrogenase (TDH) were highest ( P P