scholarly journals Induction of mRNA for phosphoenolpyruvate carboxykinase (GTP) by dexamethasone in cultured rat hepatocytes requires on-going protein synthesis

1987 ◽  
Vol 246 (1) ◽  
pp. 237-240 ◽  
Author(s):  
V L Nebes ◽  
S M Morris
Keyword(s):  
Phosphoenolpyruvate Carboxykinase ◽  
Rat Hepatocytes ◽  
Serum Free Medium ◽  
Free Medium ◽  
Serum Free ◽  
Maximum Induction ◽  
Cultured Rat Hepatocytes ◽  
Time Required ◽  
Necessary And Sufficient ◽  
Stimulation Of

Dexamethasone is necessary and sufficient to induce mRNA for phosphoenolpyruvate carboxykinase (GTP) (PEPCK) by 19-fold in rat hepatocytes cultured in serum-free medium. However, the time required for maximum induction is 16 h. The slow induction suggested that glucocorticoids regulate the expression of an intermediate gene product(s) which is required for glucocorticoid stimulation of PEPCK-gene expression. Consistent with this notion was the finding that cycloheximide completely blocked the response to dexamethasone. In contrast, cycloheximide did not block the response to a cyclic AMP analogue.

scholarly journals Stimulierung von Kulturen embryonaler Rattenzellen durch eine Proteinfraktion aus fötalem Kälberserum / Stimulation of Embryonic Rat Cells in Culture by a Protein Fraction Isolated from Fetal Calf Serum

1971 ◽  
Vol 26 (10) ◽  
pp. 1045-1048 ◽  
Author(s):  
Dieter F. Hülser ◽  
Werner Frank
Keyword(s):  
Cell Cycle ◽  
Culture Medium ◽  
Fetal Calf Serum ◽  
Surface Membrane ◽  
Calf Serum ◽  
Serum Free Medium ◽  
Free Medium ◽  
Serum Free ◽  
Membrane Potential Difference ◽  
Stimulation Of

Normal embryonic rat cells incubated in serum-free medium accumulate in G1-phase of the cell cycle. On addition of a growth-stimulating protein isolated from fetal calf serum they are triggered to proceed through the cycle, and they resume DNA-synthesis 15 to 20 hours later. In this paper it is demonstrated that the surface membrane potential difference (PD) decreases immediately after changing serum-free medium against culture medium containing either calf serum or the isolated serum protein; the original PD is restored 2 to 3 hours later. Serumprotein without growthstimulating activity does not affect the PD.A permanent rat cell line which grows independently of serum also has been tested. The PD of these cells is not significantly influenced by calf serum.

Long-term culture of rat hepatocytes on porous membranes in hormonally defined serum-free medium

1993 ◽  
Vol 7 (4) ◽  
pp. 453-459 ◽  
Author(s):  
C. Guery ◽  
J.P. Stepniewski ◽  
B. Vannier ◽  
R. Fournex ◽  
G. Lorenzon
Keyword(s):  
Rat Hepatocytes ◽  
Porous Membranes ◽  
Serum Free Medium ◽  
Free Medium ◽  
Serum Free ◽  
Long Term Culture

Microtubule disruption stimulates system A transport in cultured vascular smooth muscle cells

1995 ◽  
Vol 268 (6) ◽  
pp. C1512-C1519 ◽  
Author(s):  
J. G. Chen ◽  
A. B. Strawbridge ◽  
S. A. Kempson
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Time Course ◽  
Serum Starvation ◽  
Serum Free Medium ◽  
Free Medium ◽  
Serum Free ◽  
System A ◽  
Microtubule Disruption ◽  
Stimulation Of

This study has focused on the possible influence of microtubules for the regulation of Na(+)-dependent system A neutral amino acid transport in A10 cells, a cultured cell line derived from rat aortic vascular smooth muscle. When microtubules were disrupted by incubating cells for 5 h in serum-free medium containing colchicine, nocodazole, or vinblastine, there was a twofold increase in system A transport (Vmax change). The dose for the disruption of microtubules by colchicine was similar to the dose required for the stimulation of system A. The time course showed that system A stimulation did not occur until widespread disruption of microtubules was established. The stimulation was specific for system A; there were no changes in glucose transport and Na(+)-dependent transport of phosphate and glutamate. Serum refeeding of quiescent cells from 2 days of serum starvation led to stimulation of system A, glucose, and phosphate transport. However, only system A was activated when colchicine was added to the serum-free medium. Addition of colchicine during serum refeeding had no additive effect for the stimulation of system A. The stimulation by both colchicine and serum was blocked by cycloheximide and actinomycin D. These findings suggest that microtubule disruption may activate system A gene expression.

Effects of hormones on the maintenance and mitochondrial functions of rat hepatocytes cultured in serum-free medium

1983 ◽  
Vol 61 (7) ◽  
pp. 636-643 ◽  
Author(s):  
E. Jane Wilson ◽  
William C. McMurray
Keyword(s):  
Rat Hepatocytes ◽  
Tyrosine Aminotransferase ◽  
Serum Free Medium ◽  
Free Medium ◽  
Cultured Hepatocytes ◽  
Serum Free ◽  
Glycerophosphate Dehydrogenase ◽  
Mitochondrial Functions ◽  
Gluconeogenic Enzyme ◽  
Glucocorticoid Action

The survival and morphology of rat hepatocytes were examined in primary cell cultures that were maintained in serum-free medium supplemented with different hormones. Insulin and dexamethasone improved survival and maintenance of normal epithelial-shaped cells, although triiodothyronine did not alter cell survival or morphology when added to the medium alone or with other hormones. The level of mitochondrial α-glycerophosphate dehydrogenase and cytochromes a(+ a3), b and c, but not c1, were increased in cultured hepatocytes by triiodothyronine. Although induction of α-glycerophosphate dehydrogenase did not require serum or growth hormone, the triiodothyronine effect was potentiated by insulin plus dexamethasone. This permissive effect of dexamethasone parallels its known glucocorticoid action of increasing the activity of the gluconeogenic enzyme tyrosine aminotransferase in the cultured hepatocytes. Glucagon, which also elevated tyrosine aminotransferase activity, had no effect upon the induction of α-glycerophosphate dehydrogenase by triiodothyronine. Since the culture medium was completely defined and triiodothyronine did not alter survival or morphology of the hepatocytes, the effects upon mitochondrial functions are direct cellular actions of the thyroid hormone.

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