scholarly journals GROWTH CONTROL OF DIFFERENTIATED FETAL RAT HEPATOCYTES IN PRIMARY MONOLAYER CULTURE

1974 ◽  
Vol 62 (3) ◽  
pp. 780-791 ◽  
Author(s):  
K. Koch ◽  
H. L. Leffert
Keyword(s):  
Dna Synthesis ◽  
Primary Cultures ◽  
Growth Control ◽  
Rat Hepatocytes ◽  
Solvent System ◽  
Serum Factors ◽  
Conditioning Factors ◽  
Cellular Processes ◽  
Fetal Rat ◽  
Fraction I

Serum-deficient ≤0.00003% vol/vol) conditioned medium (CM) obtained from primary cultures of fetal rat hepatocytes initiates DNA synthesis and mitosis in homologous quiescent cultures. CM similarly prepared from 3T3 fibroblast cultures is inactive. At least two conditioning factors are involved in initiating DNA synthesis. The first of these, arginine, is obligatory, synthesized by the cells, and released into the culture medium. The second, a lipid or lipid-containing material, is stable to pH extremes (pH 2, pH 10) and chromatographs with an apparent R1 ∼0.5 on silica gel thin-layer plates using hexane-ether (4: 1) as the solvent system. It is suggested that these cultured hepatocytes enter or leave the G0 or early G1 phase of the cell cycle as determined in part by their capacity to use available conditioning factor and nutrient components of the medium, in particular, arginine. Serum factors including serum fraction I (4), insulin, and possibly, lipid-like conditioning material appear to initiate DNA synthesis by controlling cellular processes involved with the enhanced utilization and synthesis of growth-limiting nutrients.

scholarly journals GROWTH CONTROL OF DIFFERENTIATED FETAL RAT HEPATOCYTES IN PRIMARY MONOLAYER CULTURE

1974 ◽  
Vol 62 (3) ◽  
pp. 792-801 ◽  
Author(s):  
H. L. Leffert
Keyword(s):  
Dna Synthesis ◽  
Environmental Control ◽  
Primary Cultures ◽  
Growth Control ◽  
Rat Hepatocytes ◽  
Defined Medium ◽  
Crystalline Insulin ◽  
Fetal Rat ◽  
Primary Monolayer

The initiation of DNA synthesis has been studied in quiescent primary cultures of fetal rat hepatocytes using defined hormones and chemically defined medium. Preparations of crystalline insulin (0.01–10 µg/ml) or 20,000-fold purified somatomedin (0.01–1 µg/ml) are stimulatory. Growth hormone (0.025 µg/ml) and hydroxycortisone (0.025 µg/ml), 3':5'-GMP! (10-5 M) fail by themselves to initiate DNA synthesis but added together with insulin, enhance the stimulatory response by 50–100%. Thyroid hormones (L-T3, L-T4, 7.5–30 ng/ml) are by themselves without effect, but when they are added to thyroid hormone-depleted serum, the reconstituted mixtures show an enhanced capacity to initiate DNA synthesis. In contrast, glucagon (0.01 µg/ml) inhibits the insulin-stimulated response by about 50% without reducing basal DNA synthesis rates. The results described here and in the accompanying two reports indicate that environmental control over the initiation of DNA synthesis is complex, and can involve the participation of many factors. The in vitro findings are consistent with the concept that liver regeneration is hormonally controlled and raise the possibility that alterations of the intrahepatic ratio of insulin to glucagon are growth regulatory.

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.

scholarly journals GROWTH CONTROL OF DIFFERENTIATED FETAL RAT HEPATOCYTES IN PRIMARY MONOLAYER CULTURE

1974 ◽  
Vol 62 (3) ◽  
pp. 767-779 ◽  
Author(s):  
H. L. Leffert
Keyword(s):  
Dna Synthesis ◽  
Cell Attachment ◽  
Gel Filtration ◽  
Rat Hepatocytes ◽  
Hepatocyte Proliferation ◽  
Cell Multiplication ◽  
Adult Rats ◽  
Fetal Rat ◽  
Fraction I

Dialyzed fetal bovine serum contains two distinct growth-controlling macromolecular fractions: one stimulates and the other inhibits proliferation of primary cultured differentiated fetal rat hepatocytes. Both fractions are precipitated by ammonium sulfate (50% saturation, pH 7.4, 4°C). Serum fraction I (SFI, mol wt ≥ 120,000 daltons estimated by gel filtration with Bio-gel P200) appears to contain at least two factors which function, respectively, to initiate DNA synthesis (activity pH 4–10 stable) and to increase the rate at which initiated cells traverse the cell cycle (activity pH 4 and pH 10 labile). Intraperitoneal injections of SFI into adult rats have produced detectable stimulation of hepatic but not renal DNA synthesis. Serum fraction II (SFII, mol wt 40,000–80,000 daltons) suppresses in vitro incorporation of CH3-[3H]thymidine into DNA under conditions which diminish neither cell viability nor cell attachment. Mixing experiments indicate that SFI and SFII mutually antagonize each other with respect to DNA synthesis and cell multiplication. Thus, both the relative and absolute serum levels of multiple factors control in vitro fetal hepatocyte proliferation.

Events associated with EGF — Induced DNA synthesis in primary cultures of rat hepatocytes

1993 ◽  
Vol 11 (S1) ◽  
pp. S12-S14 ◽  
Author(s):  
E. Fugassa ◽  
A. Voci ◽  
M. de Marchis ◽  
M. Massajoli ◽  
F. Cesarone ◽  
...  
Keyword(s):  
Dna Synthesis ◽  
Primary Cultures ◽  
Rat Hepatocytes

Occludin expression and tight junction strand formation during replicative DNA synthesis in primary cultures of rat hepatocytes

1998 ◽  
Vol 31 (4) ◽  
pp. 169-176
Author(s):  
Takashi Kojima ◽  
Norimasa Sawada ◽  
Yasuo Kokai ◽  
Masao Yamamoto ◽  
Michio Mori ◽  
...  
Keyword(s):  
Tight Junction ◽  
Dna Synthesis ◽  
Primary Cultures ◽  
Rat Hepatocytes
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