to investigate whether the metabolism of the polyamines putrescine , spermidine and spermine is related to cellular growth rate , we have measured the activities of l-ornithine decarboxylase and s-adenosyl-l-methionine decarboxylase as well as the levels of the polyamines in rat brain tumor cells at various stages of a 7-day in vitro growth period and correlated them with the continuous changes in specific growth rate ( [ dn [ t ] /dt ] /n [ t ] ) .
C0007595
cellular growth
C0007634
cells