title: Validation of ⁹⁹mTechnetium-labeled mebrofenin hepatic extraction method to quantify meal-induced splanchnic blood flow responses using a porcine model.
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.
authors.affiliation: Dept. of Clinical Physiology, Viborg Regional Hospital, Heibergs Allé 4, 8800 Viborg, Denmark. helle.damgaard@viborg.rm.dk
authors.forename: Helle Damgaard
authors.initials: HD
authors.lastname: Zacho
authors.forename: Niels Bastian
authors.initials: NB
authors.lastname: Kristensen
authors.forename: Jens Henrik
authors.initials: JH
authors.lastname: Henriksen
authors.forename: Jan
authors.initials: J
authors.lastname: Abrahamsen
mesh_terms: D000814:Aniline Compounds; D000818:Animals; D001158:Arteries / Q000000981:diagnostic imaging / Q000378:metabolism; D004435:Eating / Q000502:physiology*; D005260:Female; D005947:Glucose / Q000378:metabolism; D005998:Glycine; D006503:Hepatic Veins / Q000000981:diagnostic imaging / Q000378:metabolism; D007098:Imino Acids / Q000493:pharmacokinetics; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000098:blood supply / Q000000981:diagnostic imaging; D019344:Lactic Acid / Q000097:blood / Q000378:metabolism; D008099:Liver / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000378:metabolism*; D023421:Models, Animal; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics; D010100:Oxygen / Q000097:blood / Q000378:metabolism; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012039:Regional Blood Flow; D015203:Reproducibility of Results; D013152:Splanchnic Circulation / Q000502:physiology*; D013552:Swine; D014684:Venae Cavae / Q000000981:diagnostic imaging / Q000378:metabolism
chemical_list: D000814:Aniline Compounds; D007098:Imino Acids; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D019344:Lactic Acid; C034837:technetium Tc 99m mebrofenin; D005947:Glucose; D010100:Oxygen; D005998:Glycine