Contribution of erythrocytes and plasma in threonine and lysine transfer across the portal drained viscera and the liver in pigs. Effect of threonineand lysine dietary supply

Contributions of erythrocytes and plasma to threonine and lysine transport across the PDV and the liver were determined in growing pigs successively f ed a threonine deficient diet and a control well-balanced diet (experiment 1) or a lysine deficient or a well-balanced diet (experiment 2). The animal s were surgically prepared for insertion of chronic catheters in the mesent eric vein (MV), the portal vein (PV), a hepatic vein (HV) and the carotid a rtery (CA). Plasma and whole blood AA concentrations in PV, HV and CA and P V and HV blood flows were determined during 6 hours of para-aminohippuric a cid constant infusion. During this period the pigs were continuously fed (1 meal per hour). The contribution of plasma to lysine and threonine transpo rt was higher in pigs fed the well balanced diets. More than 50% of threoni ne and lysine appearing in the PV and in the HV are transported by the plas ma. Our results suggest that erythrocytes are probably little involved in l ysine and threonine transfer across the liver and digestive tract of pig co ntinuously fed.