scholarly journals α-adrenergic suppression of very-low-density-lipoprotein triacylglycerol secretion by isolated rat hepatocytes

1988 ◽  
Vol 250 (2) ◽  
pp. 363-368 ◽  
Author(s):  
N P Brindle ◽  
J A Ontko
Keyword(s):  
Incubation Medium ◽  
Density Lipoprotein ◽  
Rat Hepatocytes ◽  
Phospholipid Content ◽  
Acid Uptake ◽  
Low Density ◽  
Very Low Density Lipoproteins ◽  
Isolated Rat Hepatocytes ◽  
Triacylglycerol Synthesis ◽  
Isolated Rat

The effect of adrenaline on triacylglycerol synthesis and secretion was examined in isolated rat hepatocytes. Cells were incubated with 0.5 mM-[1-14C]oleate, and the accumulation of triacylglycerol and [14C]triacylglycerol was measured in the incubation medium. Triacylglycerol appearing in the medium was present in a form with properties similar to very-low-density lipoproteins. Triacylglycerol, [14C]triacylglycerol and [14C]phospholipid contents of hepatocytes were also determined. Addition of 10 microM-(-)adrenaline decreased accumulation of glycerolipid in the incubation medium and also decreased cellular [14C]phospholipid content. Prazosin abolished these effects, whereas propranolol did not. The hormone did not affect cellular triacylglycerol content or rates of incorporation of [1-14C]oleate into cell triacylglycerol. The effect of adrenaline on the removal of newly secreted triacylglycerol and the secretion of synthesized glycerolipid was also examined. The catecholamine did not affect rates of removal of newly secreted triacylglycerol. Adrenaline did inhibit the secretion of pre-synthesized lipid by the cells, as assessed by the appearance of radiolabelled triacylglycerol from hepatocytes that had been preincubated with [1,2,3-3H]-glycerol. Adrenaline did not affect rates of fatty acid uptake by hepatocytes, but did stimulate oxidation of [1-14C]oleate, principally to 14CO2.

Role of microtubuli in secretion of very-low-density lipoprotein in isolated rat hepatocytes: Early effects of thiol reagents

Hepatology ◽  
1991 ◽  
Vol 14 (6) ◽  
pp. 1259-1268 ◽  
Author(s):  
J. Fred Nagelkerke ◽  
Bob van de Water ◽  
Irene M. Twiss ◽  
J. Paul Zoetewey ◽  
Hans J. G. M. de Bont ◽  
...  
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Rat Hepatocytes ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Isolated Rat Hepatocytes ◽  
Early Effects ◽  
Isolated Rat

scholarly journals Effect of Glucocorticoid on Secretion of Very Low Density Lipoproteins from Isolated Rat Hepatocytes

1985 ◽  
Vol 12 (6) ◽  
pp. 1475-1480
Author(s):  
Yasuko SHIKI ◽  
Seijiro MORI ◽  
Masaru KAGAMI ◽  
Kohji SHIRAI ◽  
Yasushi SAITO ◽  
...  
Keyword(s):  
Rat Hepatocytes ◽  
Low Density Lipoproteins ◽  
Low Density ◽  
Very Low Density Lipoproteins ◽  
Isolated Rat Hepatocytes ◽  
Isolated Rat

Free fatty-acid uptake by isolated rat hepatocytes

1985 ◽  
Vol 93 (4) ◽  
pp. 313-319 ◽  
Author(s):  
G. Renaud ◽  
M. E. Bouma ◽  
A. Foliot ◽  
R. Infante
Keyword(s):  
Fatty Acid ◽  
Free Fatty Acid ◽  
Rat Hepatocytes ◽  
Fatty Acid Uptake ◽  
Acid Uptake ◽  
Isolated Rat Hepatocytes ◽  
Isolated Rat

scholarly journals Lysophosphatidylcholine metabolism and lipoprotein secretion by cultured rat hepatocytes deficient in choline

1989 ◽  
Vol 260 (1) ◽  
pp. 207-214 ◽  
Author(s):  
B S Robinson ◽  
Z Yao ◽  
D J Baisted ◽  
D E Vance
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Rat Hepatocytes ◽  
Cellular Protein ◽  
Low Density Lipoproteins ◽  
Low Density ◽  
Very Low Density Lipoproteins ◽  
Phosphatidylcholine Biosynthesis ◽  
Cultured Rat Hepatocytes ◽  
Phosphatidylcholine Synthesis

The metabolism of lysophosphatidylcholine was studied in cultured rat hepatocytes deficient in choline and methionine. Even though the cells were defective in phosphatidylcholine biosynthesis, the albumin-stimulated release of lysophosphatidylcholine (1.9 nmol/h per mg of cellular protein) was similar to that in hepatocytes supplemented with choline. Albumin also stimulated (1.4-fold) the release of phosphatidylcholine from the deficient cells. The extra phosphatidylcholine and lysophosphatidylcholine in the medium were largely recovered in the albumin fraction (density greater than 1.18 g/ml), suggesting that albumin released these lipids from hepatocytes because of binding to this protein. The secretion of glycerophosphocholine was decreased by about 40% by the addition of albumin. When choline-deficient hepatocytes were supplemented with lysophosphatidylcholine, it was transported into the cells and mainly acylated to form phosphatidylcholine, which increased in mass by 30-35% in the first 4 h of incubation. Lysophosphatidylcholine was shown to be as effective as choline in restoring the secretion of very-low-density lipoproteins to normal amounts, as judged by the secretion of triacylglycerol, phosphatidylcholine and the apolipoproteins associated with very-low-density lipoproteins. Thus phosphatidylcholine synthesis via reacylation of lysophosphatidylcholine, via the CDP-choline pathway or via methylation of phosphatidylethanolamine, will satisfy the requirements for secretion of very-low-density lipoprotein from hepatocytes.

scholarly journals Stimulation of triacylglycerol synthesis in rat adipocytes by plasma very-low-density lipoproteins

1978 ◽  
Vol 176 (1) ◽  
pp. 169-174 ◽  
Author(s):  
P Thomopoulos ◽  
M Berthelier ◽  
D Lagrange ◽  
M J Chapman ◽  
M H Laudat
Keyword(s):  
Fatty Acids ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density Lipoproteins ◽  
High Density Lipoproteins ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Very Low Density Lipoproteins ◽  
Rat Adipocytes ◽  
Triacylglycerol Synthesis

The effect of human plasma lipoproteins on lipogenesis from glucose has been studied in isolated rat adipocytes. The very-low-density lipoproteins increased lipogenesis specifically, whereas low-density lipoproteins and high-density lipoproteins were without effect. Such stimulation could be reproduced with partially delipidated very-low-density lipoproteins. Nod-esterified fatty acids and glycerol were also without effect. Pretreatment of the adipocytes with trypsin did not alter the effect of very-low-density lipoprotein. The presence of Ca2+ was required for the full activation of lipogenesis. The synthesis of acylglycerol fatty acids and of acylglycerol glycerol were equally increased. The effect of very-low-density lipoprotein was not additive to that of insulin. It is suggested that very-low-density lipoprotein may directly stimulate lipogenesis in fat-cells, particularly in states when the lipoproteins are present at high concentration in the circulation.

Ascorbic acid uptake by isolated rat hepatocytes

1993 ◽  
Vol 46 (8) ◽  
pp. 1333-1338 ◽  
Author(s):  
Marie Christine Cornu ◽  
Gregory Adam Moore ◽  
Yoshio Nakagawa ◽  
Peter Moldéus
Keyword(s):  
Ascorbic Acid ◽  
Rat Hepatocytes ◽  
Acid Uptake ◽  
Isolated Rat Hepatocytes ◽  
Isolated Rat
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