## Abstract HTC cells incubated in the absence of serum for more than 14 hours have very low levels of ornithine decarboxylase, the first enzyme on the pathway of polyamine synthesis. Readdition of serum causes an increase in the activity of ODC, reaching a maximum on average 17 times above the bas
Effect of growth conditions on the activity of ornithine decarboxylase in cultured hepatoma cells. I. Effect of amino acid supply
β Scribed by Brigid L. M. Hogan; Susan Murden
- Publisher
- John Wiley and Sons
- Year
- 1974
- Tongue
- English
- Weight
- 533 KB
- Volume
- 83
- Category
- Article
- ISSN
- 0021-9541
No coin nor oath required. For personal study only.
β¦ Synopsis
Abstract
Ornithine decarboxylase activity in high density, stationary phase rat hepatoma (HTC) cells in suspension culture has an extremely short halfβlife of between 5 and 15 minutes, as measured after inhibiting protein synthesis. Following dilution of these cells into fresh medium there is a large increase in ornithine decarboxylase activity, reaching a peak often several hundred times the initial level at about four hours. At least part of this stimulation is due to an increase in the apparent halfβlife of the enzyme, to between 30 and 90 minutes. Evidence is presented that the supply of amino acids can control the turnover of ODC under some conditions. For example supplementing high density cells with glutamine, asparagine, serine, glycine and proline, either singly or together, increases ODC activity and decreases its apparent turnover. The stimulation by amino acids is enhanced by serum.
π SIMILAR VOLUMES
The effect of 835 MHz microwaves on the activity of ornithine decarboxylase (ODC) in L929 murine cells was investigated at an SAR of Γ2.5 W/kg. The results depended upon the type of modulation employed. AM frequencies of 16 Hz and 60 Hz produced a transient increase in ODC activity that reached a pe
Sodium arsenite proved effective in preventing the induction of ornithine decarboxylase (ODC) activity elicited by dilution of Friend erythroleukemia cells in fresh medium. A 50 per cent inhibition was produced at approximately 1 p~ arsenite and complete inhibition was obtained at concentrations abo
Radioactive short-chain fatty acids preferentially label glutamine relative to glutamate in brain due to compartmentation of glutamine and glutamate. To determine whether this phenomenon occurs in a single cell culture model, we examined the effect of fatty acid chain length on the synthesis as well
## Abstract The fibrinolytic activity of cells in culture varied with the type of serum employed in the growth medium. Degradation of iodinated fibrin occurred slowly when Rous sarcoma virusβtransformed chick embryo fibroblasts were grown in medium containing fetal bovine serum (FBS), and rapidly w