Effect of a Pulsatile Hepatic-Vein Pressure on the Removal and Metabolism of Chylomicrons and Chylomicron Remnants by Individual Lobes of the Perfused Rat Liver

1978 ◽  
Vol 6 (3) ◽  
pp. 581-583
Author(s):  
RONALD S. GARDNER ◽  
PETER A. MAYES
Keyword(s):  
Rat Liver ◽  
Hepatic Vein ◽  
Perfused Rat Liver ◽  
Chylomicron Remnants

scholarly journals Lipoprotein lipase enhances removal of chylomicrons and chylomicron remnants by the perfused rat liver.

1995 ◽  
Vol 36 (6) ◽  
pp. 1334-1344
Author(s):  
N Skottova ◽  
R Savonen ◽  
A Lookene ◽  
M Hultin ◽  
G Olivecrona
Keyword(s):  
Lipoprotein Lipase ◽  
Rat Liver ◽  
Perfused Rat Liver ◽  
Chylomicron Remnants

scholarly journals Apoprotein-independent binding of chylomicron remnants to rat liver membranes

1991 ◽  
Vol 279 (3) ◽  
pp. 769-773 ◽  
Author(s):  
J Borensztajn ◽  
T J Kotlar ◽  
S Y Chang
Keyword(s):  
Rat Liver ◽  
Isolated Perfused Rat Liver ◽  
Perfused Rat Liver ◽  
Hepatic Differentiation ◽  
Direct Role ◽  
Isolated Rat Liver ◽  
Liver Membranes ◽  
Chylomicron Remnants ◽  
Isolated Rat

Rat lymph chylomicrons and chylomicron remnants were treated with trypsin or Pronase. The ability of the resulting apoprotein-free lipoproteins to be taken up by the isolated perfused rat liver, and to bind to isolated rat liver membranes, was examined. Compared with control lipoproteins, the apoprotein-free chylomicrons and remnants retained unaltered their capacity to be differentiated by the intact liver and by the isolated membranes. Further, control remnants and apoprotein-free remnants competed for binding to the isolated membranes. We conclude that apoproteins are not required for the hepatic differentiation between chylomicrons and remnants, and suggest that the lipoprotein phospholipids may play a direct role in this process.

scholarly journals Uptake of phospholipid-depleted chylomicrons by the perfused rat liver

1980 ◽  
Vol 192 (3) ◽  
pp. 845-851 ◽  
Author(s):  
J Borensztajn ◽  
T J Kotlar ◽  
B J McNeill
Keyword(s):  
Phospholipase A2 ◽  
Neutral Lipid ◽  
Rat Liver ◽  
Lipid Composition ◽  
Hepatic Uptake ◽  
Perfused Rat Liver ◽  
Apparent Effect ◽  
Isolated Rat Liver ◽  
Chylomicron Remnants ◽  
Isolated Rat

1. Rat lymph chylomicrons were depleted of their surface phospholipids by treatment with pure phospholipase A2 from Crotalus adamanteus venom. 2. About 80% of the phospholipids could be removed from the chylomicrons without any apparent effect on their size, neutral lipid composition or qualitative profile of their tetramethylurea-soluble apoproteins. 3. Phospholipid-depleted chylomicrons were rapidly taken up whole by liver cells when perfused through isolated rat liver preparations. The rate of uptake was dependent on the extent of phospholipid depletion and reached a maximum (4-6.5-fold greater than control chylomicrons) when 80% of the phospholipids had been removed. 4. It is speculated that the hepatic uptake of phospholipid-depleted chylomicrons occurs by a mechanism to that of chylomicron-remnants uptake.

scholarly journals Hepatic zonation of the catabolism of arginine and ornithine in the perfused rat liver

1998 ◽  
Vol 330 (2) ◽  
pp. 627-632 ◽  
Author(s):  
Dan O'SULLIVAN ◽  
T. John BROSNAN ◽  
E. Margaret BROSNAN
Keyword(s):  
Amino Acids ◽  
Rat Liver ◽  
Hepatic Vein ◽  
Small Population ◽  
Arginase Activity ◽  
Perfused Rat Liver ◽  
Ornithine Aminotransferase ◽  
Arginine Catabolism ◽  
14Co2 Production

The metabolism of 14C-labelled arginine and ornithine was studied in the isolated, nonrecirculating, perfused rat liver. The catabolism of these amino acids required ornithine aminotransferase since treatment of rats with gabaculine, an inhibitor of this enzyme, decreased substantially the production of 14CO2 from the 14C-labelled amino acids. In the liver, ornithine aminotransferase is restricted to a small population of hepatocytes proximal to the terminal hepatic vein [Kuo, F. C., Hwu, W. L., Valle, D. and Darnell Jr., J. E. (1991) Proc. Natl. Acad. Sci. U.S.A. 88, 9468-9472], i.e. the perivenous subpopulation of hepatocytes. Catabolism of arginine requires arginase to convert arginine to ornithine which can then be catabolized through ornithine aminotransferase. The presence of arginase activity in the perivenous hepatocytes was demonstrated by experiments in which livers were perfused with [14C]arginine in both antegrade and retrograde directions. Identical rates of 14CO2 production were obtained in these experiments, a result which could only occur if the process of arginine catabolism through ornithine aminotransferase can be carried out in its entirety in the perivenous cells.

Liver Blood Flow as a Major Determinant of the Clearance of Recombinant Human Tissue-Type Plasminogen Activator

1992 ◽  
Vol 67 (01) ◽  
pp. 083-087 ◽  
Author(s):  
A de Boer ◽  
C Kluft ◽  
J M Kroon ◽  
F J Kasper ◽  
H C Schoemaker ◽  
...  
Keyword(s):  
Blood Flow ◽  
Rat Liver ◽  
Healthy Subjects ◽  
Liver Blood Flow ◽  
Major Determinant ◽  
Tissue Type ◽  
Perfused Rat Liver ◽  
Liver Model ◽  
Type Plasminogen Activator ◽  
Proportional Change

SummaryThe influence of changes in liver blood flow on the clearance of rt-PA was studied both in healthy subjects and in a perfused rat liver model. Liver blood flow in healthy subjects was documented indirectly by the clearance of indocyanine green (ICG). Exercise reduced liver blood flow on average by 57% with a 95% confidence interval (95% Cl) ranging from 51% to 62% (n = 5) and increased plasma levels of rt-PA activity (after an i. v. infusion of 18 mg of rt-PA over 120 min) by 119% (95% Cl, 58% - 203%) and rt-PA antigen by 91% (95% Cl, 30% - 140%). In the perfused rat liver model it was shown that halving or doubling of the physiological flow rate of a perfusate, containing rt-PA caused a proportional change in the clearance of rt-PA, while the extraction of rt-PA by the liver remained similar. In conclusion, liver blood flow is a major determinant of the clearance of rt-PA. This may have important implications for dosage of rt-PA in patients with myocardial infarction.

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