Validation of ⁹⁹mTechnetium-labeled mebrofenin hepatic extraction method to quantify meal-induced splanchnic blood flow responses using a porcine model

J Appl Physiol (1985). 2012 Mar;112(5):877-82. doi: 10.1152/japplphysiol.01125.2011. Epub 2011 Dec 15.

Abstract

The aim of this study was to evaluate the measurement of the total splanchnic blood flow (SBF) using a clinical diagnostic method based on Fick's principle and hepatic extraction of 99mTc-mebrofenin (99mTc-MBF) compared with a paraaminohippuric acid (pAH) dilution method in a porcine model. Another aim was to investigate whether enterohepatic cycling of 99mTc-MBF affected the SBF measurement. Five indwelling catheters were placed in each pig (n = 15) in the portal, mesenteric, and hepatic veins, as well as in the aorta and the vena cava. The SBF was measured using both methods. The portal blood flow; the intestinal and hepatic oxygen uptake; the net fluxes of oxygen, lactate, and glucose; and the extraction fraction (EF) of 99mTc-MBF were measured before and for 70 min after feeding. The mean baseline SBF was 2,961 ml/min vs. 2,762 ml/min measured by pAH and 99mTc-MBF, respectively, and increased significantly to 3,977 ml/min and 3,981 ml/min postprandially. The hepatic EF of 99mTc-MBF decreased from 40% at the start of the investigation to 16% 70 min after feeding. The arterial-portal difference in 99mTc-MBF concentration was 0.21% (P = 0.48), indicating no intestinal extraction or metabolism. The clinical method for measuring the SBF based on hepatic 99mTc-MBF extraction is robust compared with the indicator dilution method, despite the decrease seen in hepatic extraction of 99mTc-MBF. Because there was no difference in the content of 99mTc-MBF between the arterial and portal vein plasma, the SBF can be calculated from an arterial and a hepatic vein sample.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Aniline Compounds
  • Animals
  • Arteries / diagnostic imaging
  • Arteries / metabolism
  • Eating / physiology*
  • Female
  • Glucose / metabolism
  • Glycine
  • Hepatic Veins / diagnostic imaging
  • Hepatic Veins / metabolism
  • Imino Acids* / pharmacokinetics
  • Intestinal Mucosa / metabolism
  • Intestines / blood supply
  • Intestines / diagnostic imaging
  • Lactic Acid / blood
  • Lactic Acid / metabolism
  • Liver / blood supply*
  • Liver / diagnostic imaging
  • Liver / metabolism*
  • Models, Animal
  • Organotechnetium Compounds* / pharmacokinetics
  • Oxygen / blood
  • Oxygen / metabolism
  • Radionuclide Imaging
  • Radiopharmaceuticals* / pharmacokinetics
  • Regional Blood Flow
  • Reproducibility of Results
  • Splanchnic Circulation / physiology*
  • Swine
  • Venae Cavae / diagnostic imaging
  • Venae Cavae / metabolism

Substances

  • Aniline Compounds
  • Imino Acids
  • Organotechnetium Compounds
  • Radiopharmaceuticals
  • Lactic Acid
  • technetium Tc 99m mebrofenin
  • Glucose
  • Oxygen
  • Glycine