Splanchnic acid-base status and urea metabolism in uremic rats

Acidosis may alter hepatosplanchnic amino acid metabolism during uremia.26 uremic rats and 30 controls were studied for portal and arterial acid-base balance and urea synthesis during enteral nutrition. Uremic rats exhibited increased (p < 0.05) portal H+ (47.20 ± 0.018 vs 43.05 ± 0.49 nmol/I) and decreased HCO3− (19.45 ± 0.69 vs 23.01 ± 0.57 mmol/l) without significant change in arterial H+ (45.29 ± 1.13 vs 43.15 ± 0.49) and HCO3− (18.41 ± 0.64 vs 19.59 ± 0.49). Porto-arterial difference showed an intestinal HCO3− release in controls only (3.53 ± 0.64 mmol/l). Urea synthesis rate was significantly enhanced by enteral nutrition in controls only: 54.33 ± 17.3 vs −11.8 ± 20 μmol/min 100g body mass. Thus, during uremia, portal acidosis was associated with a decrease in enteral nutrition-induced urea synthesis.