Action of Polyamines on Ribonucleic Acid and Protein Synthesis during Ontogeny of Human Fetal Liver

Abstract
A higher rate of RNA synthesis in human fetal liver cells was found during the early age of gestation, after a drop, it gradually increases to a maximum value between 18 and 22 weeks, followed by a sharp decrease at later period of gestation. Total polyamine content of fetal liver tissue shows a similar trend. However, when liver cell suspension was incubated with exogenous spermine, spermidine and putrescine there is a dose-dependent inhibition in RNA synthesis. Protein synthesis in human fetal liver cells was stimulated with lower doses of spermine, spermidine and putrescine and inhibited at higher doses. The optimum dose for stimulation and the degree of stimulation was, however, not the same for fetuses of different gestational ages.