CIVETAN   23983
CENTRO DE INVESTIGACION VETERINARIA DE TANDIL
Unidad Ejecutora - UE
artículos
Título:
Splanchnic net balance of oxygen and metabolites in response to a continuous mesenteric vein infusion of ammonium in sheep
Autor/es:
RECAVARREN, MARIANA INÉS; MILANO, GUILLERMO DANIEL
Revista:
JOURNAL OF ANIMAL PHYSIOLOGY AND ANIMAL NUTRITION
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 2012
ISSN:
0931-2439
Resumen:
In order to simulate daily episodes of high NH4+ absorption associated with the intake of diets with high N content, four wethers (42 ± 3.4 kg body weight), fitted with permanent catheters in the femoral artery and splanchnic vessels, were infused with 340 µmol NH4+HCO3-/min into the mesenteric vein for 3 h, during the morning meal, over 7 consecutive days. On the 7th day, mass transfers of NH4+, urea, glucose, lactate, ß-OH-butyrate and O2 were measured across portal-drained viscera (PDV), liver and splanchnic tissues during the last 90 min of the NH4+HCO3- infusion. Measurements were repeated on the following day, at the same time, without the NH4+HCO3- infusion. Plasma NH4+concentration in the portal vein (+332 μM; P=0.006), portal NH4+ absorption (+424 μmol/min; P< 0.001) and liver NH4+ uptake (+375 µmol/min; P=0.003) and urea N production (+338 µmol/min; P=0.059) were higher during NH4+HCO3- infusion. Mass transfers of urea, glucose, lactate, ß-OH-butyrate and O2 across the PDV, and glucose, lactate, ß-OH-butyrate and O2 across the liver were not altered by the NH4+HCO3- infusion. Results suggest that a daily, discontinuous increase in portal NH4+ flow during a meal stimulates liver NH4+ removal and urea N production but does not significantly affect liver glucose production and O2 consumption in sheep.