The Anti-Anabolic Effect of Glucagon on Albumin Synthesis by the Isolated Perfused Rat Liver

1973 ◽  
Vol 45 (3) ◽  
pp. 13P-13P
Author(s):  
A. S. Tavill ◽  
Joan Metcalfe ◽  
Elizabeth Black ◽  
R. Hoffenberg
Keyword(s):  
Rat Liver ◽  
Isolated Perfused Rat Liver ◽  
Anabolic Effect ◽  
Perfused Rat Liver ◽  
Albumin Synthesis

Effect of alcohol on albumin synthesis by the isolated perfused rat liver

1973 ◽  
Vol 26 (11) ◽  
pp. 1191-1194 ◽  
Author(s):  
Ralph E. Kirsch ◽  
Lesley O’C. Frith ◽  
Robin H. Stead ◽  
Stuart J. Saunders
Keyword(s):  
Rat Liver ◽  
Isolated Perfused Rat Liver ◽  
Perfused Rat Liver ◽  
Albumin Synthesis

scholarly journals The effects of amino acids on albumin synthesis by the isolated perfused rat liver

1972 ◽  
Vol 129 (4) ◽  
pp. 805-809 ◽  
Author(s):  
L. Kelman ◽  
S. J. Saunders ◽  
S. Wicht ◽  
L. Frith ◽  
A. Corrigall ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Rat Liver ◽  
Normal Values ◽  
Isolated Perfused Rat Liver ◽  
Perfused Rat Liver ◽  
Albumin Synthesis ◽  
Isoleucine Leucine ◽  
Blood Concentrations ◽  
Normal Peripheral Blood

Albumin synthesis was measured in the isolated perfused rat liver by using the livers of both well-fed and starved rats. Starvation markedly decreased albumin synthesis. The livers from starved rats were unable to increase synthesis rates after the addition to the perfusates of single amino acids or the addition of both glucagon and tryptophan. Arginine, asparagine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, threonine, tryptophan and valine, added together to ten times their normal peripheral blood concentrations, restored synthesis rates to normal. The plasma aminogram (i.e. the relative concentrations, of amino acids) was altered by depriving rats of protein for 48h. The use of blood from the deprived rats as perfusate, instead of normal blood, decreased albumin synthesis rates significantly by livers obtained from well-fed rats. The addition of single amino acids, including the non-metabolizable amino acid, α-aminoisobutyric acid, to the above mixture increased albumin synthesis rates to normal values. It is concluded that amino acids play an important role in the control of albumin synthesis and that more than one mechanism is probably involved.

scholarly journals Hepatic albumin and urea synthesis: The mathematical modelling of the dynamics of [14C]carbonate-derived guanidine-labelled arginine in the isolated perfused rat liver

1975 ◽  
Vol 150 (3) ◽  
pp. 495-509 ◽  
Author(s):  
A S Tavill ◽  
D Nadkarni ◽  
J Metcalfe ◽  
E Black ◽  
R Hoffenberg ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Rat Liver ◽  
Specific Radioactivity ◽  
Compartmental Analysis ◽  
Constant Infusion ◽  
Isolated Perfused Rat Liver ◽  
Urea Synthesis ◽  
Perfused Rat Liver ◽  
Albumin Synthesis ◽  
Product Analysis

A mathematical model was constructed to define the dynamics of incorporation of radioactivity into urea carbon and the guanidine carbon of arginine in plasma albumin after the rapid intraportal-venous administration of Na214CO3 in the isolated perfused rat liver. 2. The model was formulated in terms of compartmental analysis and additional experiments were designed to provide further information on subsystem dynamics and to discriminate between alternative model structures. 3. Evidence for the rapid-time-constant of labelling of intracellular arginine was provided by precursor-product analysis of precursor [14C]carboante and product [14C]urea in the perfusate. 4. Compartmental analysis of the dynamics of newly synthesized urea was based on the fate of exogenous [13C]urea, endogenous [14C]urea and the accumulation of [12C]urea in perfusate water, confirming the early completion of urea carbon labelling, the absence of continuing synthesis of labelled urea, and the presence of a small intrahepatic urea-delay pool. 5. Analysis of the perfusate dynamics of endogenously synthesized and exogenously administered [6-14C]arginine indicated that although the capacity for extrahepatic formation of [14C]-urea exists, little or no arginine formed within the intrahepatic urea cycle was transported out of the liver. However, the presence of a rapidly turning-over intrahepatic arginine pool was confirmed. 6. On the basis of these subsystem analyses it was possible to offer feasible estimations for the parameters of the mathematical model. However, it was not possible to stimulate the form and magnitude of the dynamics of newly synthesized labelled urea and albumin which were simultaneously observed after administration of [14C]carbonate on the basis of a preliminary model which postulated that both products were derived from a single hepatic pool of [16-14C]arginine. On the other hand these observed dynamics could be satisfied to a two-compartment arginine model, which also provided an explanation for discrepancies observed between albumin synthesis measured radioisotopically and immunologically. This was based on a relative overestimation of [14C]urea specific radioactivity resulting from the rapid dynamics of [14C]carbonate and the [14C]urea subsystem relative to the labelled albumin subsystem. The effects of arginine compartmentalization could be minimized in the model by minor slowing of the rate of [14C]carbonate turnover or by constant infusion of [14C]carbonate, both of which permitted valid determination of albumin-synthesis rates.

[14C]Carbonate Kinetics and Albumin Synthesis by the Isolated Perfused Rat Liver

1973 ◽  
Vol 45 (1) ◽  
pp. 3P-3P
Author(s):  
A. S. Tavill ◽  
D. Nadkarni ◽  
J. Metcalfe ◽  
E. Black ◽  
R. Hoffenberg ◽  
...  
Keyword(s):  
Rat Liver ◽  
Isolated Perfused Rat Liver ◽  
Perfused Rat Liver ◽  
Albumin Synthesis

Release of Colony-Stimulating Activity from the Isolated Perfused Rat Liver

1976 ◽  
Vol 50 (6) ◽  
pp. 539-544
Author(s):  
A. Howell ◽  
W. G. E. Cooksley ◽  
C. J. Danpure
Keyword(s):  
Rat Liver ◽  
Colony Formation ◽  
Rat Plasma ◽  
Isolated Perfused Rat Liver ◽  
Perfused Rat Liver ◽  
Albumin Synthesis ◽  
Isolated Rat Liver ◽  
Colony Stimulating Activity ◽  
Isolated Rat

1. Colony-stimulating activity appeared in the perfusate of the isolated rat liver during perfusions with either whole rat blood, rat plasma or an artificial perfusate of Eagle's medium and albumin. 2. Dialysable inhibitors of colony formation were also released during perfusions. 3. Colony-stimulating activity in artificial perfusate could be enhanced by the addition of rat plasma in vitro. Concentrations of cycloheximide that inhibited albumin synthesis by the liver did not inhibit the release of colony-stimulating activity.

A Comparison of Plasminogen Activators Derived from Rat Plasma, Primary Rat Hepatocytes and Isolated Perfused Rat Liver

1982 ◽  
Vol 47 (02) ◽  
pp. 166-172 ◽  
Author(s):  
Yoav Sharoni ◽  
Maria C Topal ◽  
Patricia R Tuttle ◽  
Henry Berger
Keyword(s):  
Rat Liver ◽  
Isoelectric Point ◽  
Rat Hepatocytes ◽  
Cell Types ◽  
Plasminogen Activators ◽  
Rat Plasma ◽  
Isolated Perfused Rat Liver ◽  
Perfused Rat Liver ◽  
Molecular Weights ◽  
Physiological Relevance

SummaryOf the two cell types it was possible to culture from the dissociated rat liver, hepatocytes and Kupffer cells, only the former were fibrinolytically active. Rat hepatocytes during the first 24 hr in culture secreted two plasminogen activators with molecular weights identical to those found in rat plasma, an 80,000-dalton form (PA-80) and a 45,000-dalton form (PA-45). Partially purified preparations of plasminogen activators from both sources were subjected to isoelectric focusing (IEF) to compare characteristics further. There were three distinct peaks of PA-45 in each preparation with isoelectric points of 7.1, 7.2 and 7.4; all electrophoretic forms had the same low affinity to fibrin. PA-80 from both sources displayed similar IEF profiles with forms ranging from pH values of 7 to 8, all with the same high affinity to fibrin. The major form of PA-80 in the plasma preparation had an isoelectric point of 7.9 whereas that in the hepatocyte preparation had an isoelectric point of 7.6. The isolated perfused rat liver was also shown to produce both PA-80 and PA-45 emphasizing the physiological relevance of the findings with hepatocytes. It is concluded that in the rat hepatocytes contribute to the plasma profile with regard to the plasminogen activator content.

Troxerutin protects the isolated perfused rat liver from a possible lipid peroxidation by coumarin

Phytomedicine ◽  
2005 ◽  
Vol 12 (1-2) ◽  
pp. 52-61 ◽  
Author(s):  
B.S. Adam ◽  
R. Pentz ◽  
C.P. Siegers ◽  
O. Strubelt ◽  
M. Tegtmeier
Keyword(s):  
Lipid Peroxidation ◽  
Rat Liver ◽  
Isolated Perfused Rat Liver ◽  
Perfused Rat Liver
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