The stimulation of the initiation of DNA synthesis by fibroblast growth factor in Swiss 3T3 cells: interactions with hormones during the pre-replicative phase.
Fibroblast Growth Factor (FGF) stimulates quiescent Swiss 3T3 cells to initiate DNA synthesis and divide. Cells begin to enter the S-phase after a lag of 13--15 hr, and the rate of initiation of DNA synthesis in the population can be quantified by a first order rate constant, k. A subsaturating concentration of FGF may establish the lag phase, while the value of k is dependent on the FGF concentration present during the second half of the lag phase. Insulin and hydrocortisone enhance the effect of FGF by increasing k without changing the lag phase, and they can act when added at any time after FGF. Prostaglandin E1 (PGE1) causes a decrease in k and a lengthening of the lag phase, and acts only when added during the first 8 hr. None of these agents stimulate DNA synthesis in the absence of FGF.
D000818:Animals; D000242:Cyclic AMP / Q000032:analysis; D004247:DNA / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D005347:Fibroblasts / Q000032:analysis / Q000378:metabolism*; D006133:Growth Substances / Q000494:pharmacology*; D006854:Hydrocortisone / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology; D051379:Mice; D011458:Prostaglandins E / Q000494:pharmacology; D011460:Prostaglandins F / Q000494:pharmacology
D006133:Growth Substances; D007328:Insulin; D011458:Prostaglandins E; D011460:Prostaglandins F; D004247:DNA; D000242:Cyclic AMP; D006854:Hydrocortisone