Isolation of mutant mammalian cells altered in polyamine transport.

Chinese hamster ovary and rat myoblast cells resistant to the toxic action of methylglyoxal bis guanylhydrazone (MGBG), an antimitotic agent and inhibitor of polyamine synthesis, have been isolated by single step selection. Mutagenesis with ethyl methanesulfonate increases the recovery of the variants at least 30-fold. Intracellular accumulation of MGBG is greatly reduced in resistant cells. This property is accompanied by a 99% decrease in the uptake of all three naturally occurring polyamines. Both the resistant phenotype and the defect in polyamine transport behave recessively in somatic cell hybrids.