Elevated intracellular concentrations of cyclic AMP inhibited serum‐stimulated, density‐arrested BALB/c‐3T3 cells in mid G1
- 1 January 1982
- journal article
- research article
- Published by Wiley in Journal of Cellular Biochemistry
- Vol. 19 (1), 93-103
- https://doi.org/10.1002/jcb.240190108
Abstract
The stimulation of DNA synthesis in quiescent, density‐arrested BALB/c‐3T3 cells by platelet‐derived growth factor in plasma‐supplemented medium was inhibited by the presence of isobutylmethylxanthine (IBMX) and cholera toxin, although neither IBMX or cholera toxin when used alone inhibited the stimulation of DNA synthesis. The cells were reversibly inhibited in mid G1 at a point 6 hr prior to the initiation of DNA synthesis. The inhibition of cell cycle traverse was associated with a 10–15 fold increase in cellular cyclic AMP concentration over basal levels. The reversal of this inhibition by removal of IBMX was correlated with a dramatic decrease in cyclic AMP levels. The traverse of late G1 and the initiation of DNA synthesis after release from the cholera toxin and IBMX inhibition was dependent on the presence of plasma in the medium. Either somatomedin C (10–20 ng/ml) or insulin (10−6–10−5 M) completely replaced the plasma requirement for late G1 progression and entry into S phase. Once the inhibited cells were released from the IBMX and cholera toxin block a subsequent increase in cyclic AMP did not prevent entry into S phase. The presence of cholera toxin alone inhibited the stimulation of human dermal fibroblasts. The elevation of intracellular cyclic AMP levels in the human dermal fibroblasts by cholera toxin was two to three fold greater than that found in the BALB/c‐3T3 cells in the presence of cholera toxin and IBMX.Keywords
This publication has 21 references indexed in Scilit:
- Increases in cyclic AMP potentiate competence formation in BALB/c‐3T3 cellsJournal of Cellular Physiology, 1982
- Kinetics of cAMP inhibition of DNA synthesis in bovine adrenocortical cellsMolecular and Cellular Endocrinology, 1980
- Cholera toxin and analogues of cyclic AMP stimulate the growth of cultured human mammary epithelial cellsJournal of Cellular Physiology, 1980
- Cholera toxin stimulates division of 3T3 cellsJournal of Cellular Physiology, 1979
- Dual control of cell growth by somatomedins and platelet-derived growth factor.Proceedings of the National Academy of Sciences, 1979
- Induction of DNA synthesis in BALB/c 3T3 cells by serum components: Reevaluation of the commitment processProceedings of the National Academy of Sciences, 1977
- Radioimmunoassay of a human serum growth factor for Balb/c-3T3 cells: derivation from platelets.Proceedings of the National Academy of Sciences, 1977
- DNA synthesis in cultured human fibroblasts: Regulation by 3′ : 5′‐cyclic ampJournal of Supramolecular Structure, 1976
- Epidermal Growth Factor: Receptors in Human Fibroblasts and Modulation of Action by Cholera ToxinProceedings of the National Academy of Sciences, 1973
- c-AMP and the cell cycle: Inhibition of growth stimulationExperimental Cell Research, 1973