Kinetics of Distribution of D2O and Antipyrine in Isolated Perfused Rat Liver

• Published in: The American journal of physiology Vol. 192; no. 3; pp. 531 - 537
• Main Authors: Thompson, Alan M, Cavert, H. Mead, Lifson, Nathan
• Format: Journal Article
• Language: English
• Published: United States 01-03-1958
• Subjects: Aminopyrine - analogs & derivatives; Animals; Antipyrine; Deuterium - metabolism; Extracorporeal Circulation; Kinetics; Liver - metabolism; Old Medline; Physics; Rats; DEUTERIUM/metabolism; AMINOPYRINE/related compounds; LIVER/metabolism
• ISSN: 0002-9513; 2163-5773
• DOI: 10.1152/ajplegacy.1958.192.3.531

1 From the Department of Physiology, University of Minnesota Medical School, Minneapolis, Minnesota
Isolated rat livers were perfused via the portal vein with a blood-Ringer mixture containing a constant inflow concentration of D 2 O and, in some cases, antipyrine. The rate of increase of outflow concentration was studied, comparisons being made between D 2 O, antipyrine and a theoretical outflow curve based on completely flow-limited distribution. The effect of flow rate on the deviation of D 2 O from theoretical was also studied. The results indicate that exchange of D 2 O and antipyrine between blood and tissue in the perfused rat liver is extremely rapid relative to the rate of blood supply of these substances to the organ, even at flows several times that occurring in vivo . In the average experiment the average D 2 O concentration in the liver during the early period of the perfusion was about 90% of the mixed venous concentration. The factors responsible for the failure of D 2 O to distribute maximally, particularly tissue perfusion heterogeneity and diffusion limitation, are discussed. Although quantitation of the difference is difficult, antipyrine appears to distribute somewhat more rapidly than D 2 O due to its greater solubility in cell membranes.