Gastroenterology
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Portal and hepatic indicator dilution curves (IDC) were obtained after injection of a mixture of 51Cr-labeled red blood cells ([51Cr]RBC) and 125I-albumin microaggregates (125I-AMA) into the cranial mesenteric artery in dogs. The extraction (E) of 125I-AMA from portal blood was measured during one passage through the hepatic reticuloendothelial system. Using [51Cr]RBC as a vascular reference substance, E-125I-AMA was calculated by comparing simultaneous [51Cr]RBC and 125I-AMA portal and hepatic IDC, and was expressed as percentage of 125I-AMA flowing through the portal vein. ⋯ In cirrhotics, the decreased E-125I-AMA can be related to part of portal blood bypassing Kupffer cells (intrahepatic portohepatic shunts) and/or to sinusoidal changes responsible for ineffective phagocytosis. Thus, E-125I-AMA can be used as an estimation of the functional portal blood supply to the liver in cirrhotics. Using portal and hepatic IDC after injection of [51Cr]RBC and 125I-AMA into the superior mesenteric artery, the portal fraction of hepatic blood flow and the functional portal blood supply can be estimated simultaneously in patients with portal hypertension before portacaval shunts.