Ethanol elimination kinetics in human liver and pig liver in vivo
Keiding, S.; Johansen, S.; Midtbøll, I.; Rabøl, A.; Christiansen, L.
American Journal of Physiology 237(4): E316-E324
1979
ISSN/ISBN: 0002-9513 PMID: 495711 Document Number: 148448
The kinetics of ethanol elimination in intact liver was studied in human livers and pig livers in situ, examined by hepatic vein catheterization, and in perfused pig livers. The elimination kinetics was analyzed by a mathematical model of the sinusoidal perfusion. It assumes that parallel liver sinusoids are prefused in a parallel manner with unidirectional flow with a single common transit time and that 1 way metabolic removal in the hepatocytes follows Michaelis-Menten kinetics. Ethanol was given as successive constant infusions so that successive steady-state periods were obtained with mean ethanol concentrations from about 50-11,000 .mu.M. The ethanol concentration was determined in input and output blood samples, and the hepatic blood flow rate was measured by means of a constant infusion of indocyanine green. The mathematical model fitted the data to within the measurement uncertainty. The estimated maximal elimination rate, Vmax, ranged from 0.80-1.26 mmol.cntdot.min-1.cntdot.kg-1 liver in 3 human subjects (estimated liver wt = 2% of body wt), from 0.62 to 1.63 mmol.cntdot.min-1.cntdot.kg-1 liver in 8 in situ pig livers, and from 0.46 to 0.65 mmol.cntdot.min-1.cntdot.kg-1 liver in 5 perfused pig livers. The half saturation concentration, Km, ranged from 0.09-0.26 mM in the human liver, from 0.10-0.80 mM in the in situ pig liver and from 0.14-0.92 mM in the perfused pig liver.