Gestational-age-dependent concentrations of polyamines, their conjugates and metabolites in urine and amniotic fluid.

The metabolism and fate of polyamines during cell proliferation, differentiation, and cell loss were investigated by measuring the concentration of polyamines, their conjugates and some of their metabolites in amniotic fluid of 24 subjects, and in urine of 85 women during pregnancy. The increase of putrescine and spermine in acid-hydrolysed urines during pregnancy appeared to be almost completely due to increases in monoacetylated putrescine and N1,N12 diacetylated spermine, respectively. The latter two were the quantitatively most important polyamines in amniotic fluid. In urine, monoacetylated putrescine showed the highest levels at the end of pregnancy, whereas N1,N12 diacetylated spermine reached the highest values at about 32 weeks gestation. It was impossible to establish whether extracellular monoacetylated putrescine is linked either to cell growth or cell loss. The appearance of N1,N12 diacetylated spermine is probably due to cell loss and dependent on the degree of differentiation during fetal development. The decline and eventual disappearance of urinary N1,N12 diacetylated spermine during the first 2 years after birth may be coherent with maturation of the FAD-dependent polyamine oxidase activity.