Effect of the site of infusion of para-aminohippuric acid (PAH) on portal blood flow

摘要

The in vivo measurement of nutrient absorption is a necessary step in the characterisation of nutrient requirements of animals. In this context, the determination of portal blood flow is critical. When dilution techniques are used for such measurements, eg using PAH, a homogeneous mixing of the marker in the blood is a prerequisite for the validity of the results. In this respect, Ortigues et al (1994, J Agr Sci Camb, 122, 299-308) suggested that mixing of PAH in portal blood could be improved by infusing PAH simultaneously via a ruminal (RV) and a mesenteric (MV) vein, compared to a MV only. These authors, however, studied the influence of the PAH infusion site in different animals such that the infusion site effect may have been biased by an animal or catheter placement effect. The objective of the present work was to compare in the same animals the influence of a MV + RV infusion with that of a MV infusion on portal blood flow determination.