scholarly journals Growth control of differentiated fetal rat hepatocytes in primary monolayer culture. IX. Specific inhibition of DNA synthesis initiation by very low density lipoprotein and possible significance to the problem of liver regeneration.

1976 ◽  
Vol 70 (1) ◽  
pp. 20-32 ◽  
Author(s):  
H L Leffert ◽  
D B Weinstein
Keyword(s):  
Dna Synthesis ◽  
Low Density Lipoprotein ◽  
Growth Control ◽  
Density Lipoprotein ◽  
Rat Hepatocytes ◽  
Hepatocyte Proliferation ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Rat Serum ◽  
Fetal Rat

Rat serum very low density lipoprotein (VLDL) inhibits initiation of DNA synthesis in fetal rat hepatocyte cultures; cells engaged in synthesizing DNA resist inhibition. VLDL action is specific and apparently blocks prereplicative protein synthesis. These and other results, from studies of altered blood VLDL levels and [3H] thymidine incorporation into isolated liver nuclei in 70% hepatectomized normal and mutant hyperlipoproteinemic rats, as well as from infusion studies with a "mitogenic" hormone solution, suggest that hepatic VLDL metabolism is linked to the suppression of hepatocyte proliferation.

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 Calcium-antagonists inhibit secretion of very-low-density lipoprotein from cultured rat hepatocytes

1987 ◽  
Vol 247 (2) ◽  
pp. 433-439 ◽  
Author(s):  
J O Nossen ◽  
A C Rustan ◽  
C A Drevon
Keyword(s):  
Calcium Antagonists ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Rat Hepatocytes ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Maximal Effect ◽  
Dependent Manner ◽  
Triacylglycerol Synthesis ◽  
Cultured Rat Hepatocytes

The effects of different calcium-antagonists on secretion of very-low-density lipoprotein (VLDL) from cultured rat hepatocytes were examined. Verapamil (an inhibitor of voltage-dependent calcium channels) and EGTA (a calcium chelator) decreased VLDL-triacylglycerol secretion in a concentration-dependent manner, with maximum inhibition (about 90%) at 0.2 mM-verapamil and 5 mM-EGTA. Inorganic calcium-antagonists such as lanthanum, nickel, cobalt and manganese decreased secretion of VLDL-triacylglycerol by 55-95%, whereas the calcium-agonist barium did not affect secretion. Inhibition of VLDL-triacylglycerol secretion appeared within 30 min, without inhibition of triacylglycerol synthesis. Pulse-chase experiments revealed that verapamil and cobalt inhibited the secretory pathway itself. Cobalt showed a concentration-dependent inhibition of VLDL-triacylglycerol secretion, with maximal effect at 8 mM. Although inhibition by cobalt was not completely reversible, Trypan Blue exclusion and lactate dehydrogenase leakage indicated that the hepatocytes were not injured by cobalt or any of the other calcium-antagonists tested. Inhibition of protein synthesis by cycloheximide did not affect triacylglycerol secretion (up to 2 h), and the observed effects were therefore probably not due to impaired production of apolipoproteins. Taken together, these results suggest that calcium is important for secretion of VLDL particles.

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