155 The effect of dietary n-3 fatty acids on the assembly and secretion of very low density lipoprotein by isolated rat hepatocytes

1997 ◽  
Vol 25 (4) ◽  
pp. S683-S683 ◽  
Author(s):  
ABDEL-MALEK HEBBACHI ◽  
GEOFFREY. F. GIBBONS
Keyword(s):  
Fatty Acids ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Rat Hepatocytes ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Isolated Rat Hepatocytes ◽  
Isolated Rat

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 Actin microfilaments, cell shape, and secretory processes in isolated rat hepatocytes. Effect of phalloidin and cytochalasin D.

1979 ◽  
Vol 81 (3) ◽  
pp. 592-607 ◽  
Author(s):  
M Prentki ◽  
C Chaponnier ◽  
B Jeanrenaud ◽  
G Gabbiani
Keyword(s):  
Cell Shape ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Rat Hepatocytes ◽  
Cytochalasin D ◽  
Very Low Density Lipoprotein ◽  
Actin Microfilaments ◽  
Isolated Rat Hepatocytes ◽  
Lipoprotein Secretion ◽  
Isolated Rat

The effects of phalloidin and cytochalasin D, drugs which, respectively, stabilize and destabilize actin microfilaments, have been tested on isolated rat hepatocytes. Both drugs produced a modification of cell shape, characterized by protrusions bulging from the cytoplasm. In phalloidin-treated hepatocytes, an accumulation of actin microfilamentous network was detectable at the base of each protrusion by electron microscopy, immunofluorescence, and HMM decoration. This accumulation of microfilaments was absent in cytochalasin D-treated cells. The release of triglycerides, an index of very low density lipoprotein secretion, was inhibited by phalloidin or cytochalasin D, and accompanied by an increase in cellular triglycerides. At the electron microscope examination, triglyceride accumulation was represented by fat droplets and vesicle-enclosed, very low density lipoprotein-like particles. Total protein and albumin secretion was only very slightly modified by either one of these drugs. With the use of various phalloidin analogs, a correlation was observed between their respective ability to stabilize F-actin in vitro, and their effects on cell shape and triglyceride secretion. In conclusion, phalloidin, and cytochalasin D: (a) modify the shape of isolated hepatocytes; (b) inhibit lipoprotein secretion. These effects possibly result from a modification of actin microfilament function.

Comparison of the effects of dietary saturated, mono-unsaturated and polyunsaturated fatty acids on very-low-density lipoprotein secretion when delivered to hepatocytes in chylomicron remnant-like particles

2007 ◽  
Vol 35 (3) ◽  
pp. 440-441 ◽  
Author(s):  
I. Lopez-Soldado ◽  
M. Avella ◽  
K.M. Botham
Keyword(s):  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Olive Oil ◽  
Corn Oil ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Rat Hepatocytes ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Chylomicron Remnant

The effect of chylomicron remnant-like particles (CRLPs) enriched in saturated, mono-unsaturated or n−6 polyunsaturated fatty acids (derived from palm, olive or corn oil, respectively) on the secretion of VLDL (very-low-density lipoprotein) by rat hepatocytes in culture was investigated. CRLPs were incubated with cultured hepatocytes for 5 h. The medium was then removed and the secretion of cholesterol and triacylglycerol (TAG) into the whole medium during the following 16 h was determined. After exposure of the cells to olive oil as compared with corn and palm oil CRLPs, secretion of TAG into the medium was decreased. The TAG content of the cells was also lower in experiments with olive oil as compared with corn oil CRLPs. The levels of apoB48 (apolipoprotein B48) found in the medium remained unchanged after the exposure of the cells to the different types of remnants. These findings indicate that the type of fat in the diet directly affects VLDL lipid secretion on delivery to the liver in chylomicron remnants.

scholarly journals The lipolysis/esterification cycle of hepatic triacylglycerol. Its role in the secretion of very-low-density lipoprotein and its response to hormones and sulphonylureas

1992 ◽  
Vol 284 (2) ◽  
pp. 457-462 ◽  
Author(s):  
D Wiggins ◽  
G F Gibbons
Keyword(s):  
Fatty Acids ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Intracellular Pool ◽  
Hepatocyte Cultures ◽  
Vldl Secretion ◽  
Vldl Assembly ◽  
Hepatic Triacylglycerol

In hepatocyte cultures maintained in the absence of extracellular fatty acids, at least 70% of the secreted very-low-density lipoprotein (VLDL) triacylglycerol was derived via lipolysis of intracellular triacylglycerol. This proportion was unchanged when the cells were exposed for 24 h to insulin or glucagon, hormones which decreased the overall secretion of intracellular triacylglycerol, or to chloroquine or tolbutamide, agents which inhibit lysosomal lipolysis. The rate of intracellular lipolysis was 2-3-fold greater than that required to maintain the observed rate of triacylglycerol secretion. Most of the fatty acids released were returned to the intracellular pool. Neither insulin nor glucagon had any significant effect on the overall lipolysis and re-esterification of intracellular triacylglycerol. In these cases a greater proportion of the released fatty acids re-entered the cellular pool, rather than being recruited for VLDL assembly. Tolbutamide inhibited intracellular lipolysis, but suppressed VLDL secretion to a greater extent. 3,5-Dimethylpyrazole did not affect lipolysis or VLDL secretion. The increased secretion of VLDL triacylglycerol observed after exposure of cells to insulin for 3 days was not accompanied by an increased rate of intracellular lipolysis. However, a larger proportion of the triacylglycerol secreted under these conditions may not have undergone prior lipolysis.

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