We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Polyamine Biosynthesis in Arginine-Starved and Refed Rats.
- Authors
SCHERTEL, Bodo; EICHLER, Wolfgang
- Abstract
Growth of rats fed with a synthetic diet was studied under control conditions (arginine-rich), arginine starvation, and arginine starvation/refeeding. Hepatic polyamine concentrations and ornithine decarboxylase (ODC-)activity were determined for each population. In the livers of arginine-starved rats putrescine was decreased to half the control content within 8 days; upon refeeding, it returned to control levels within another 8 days. Spermidine content in liver tissue of arginine-starved rats remained rather stable for 7 days, but thereafter dropped to half the original value within two days. Refeeding for a period of 11 days was not enough to restore the Spermidine content. The effects of arginine starvation/refeeding on spermine were very similar to those of Spermidine. ODC specific activity, when correlated with growth, was higher in livers of arginine-starved rats than in control animals. Refeeding caused a decrease in ODC-activity although growth arrest was completely released. This apparent uncoupling of growth and ODC stimulation supports the theory that ODC in rat liver is regulated at three levels: first the growth-related component which is observed after stimulation by growth-hormone; second the known feed back control by polyamines, e.g. via antizyme; third the regulation at the level of the substrate supply which has been shown in this work. This is not a unique finding since very similar results have been obtained in previous experiments with the protozoan Tetrahymena thermophila. A remarkable observation of these assays was that Lornithine, when added to the arginine-free diet was not able to substitute for L-arginine in directing growth and growth related processes.
- Publication
Biological Chemistry, 1991, Vol 372, Issue 1, p27
- ISSN
1431-6730
- Publication type
Article