Effects of spermidine synthase inhibition in cultured chick embryo fibroblasts.

The administration of bis-cyclohexylammonium sulfate (BCHS), a spermidine synthase inhibitor, to in vitro cultures of chick embryo fibroblasts caused a decrease in cellular spermidine levels and an increase in putrescine and spermine. Cell proliferation rate and DNA synthesis were also inhibited. As protein synthesis did not change, it would seem that low levels of cellular spermidine inhibit cell growth depressing DNA synthesis.