[Studies on polyamines in the developing rats tissues]

Polyamines were determined by a rapid and simplified HPLC method, in the tissues of normal developing and experimental IUGR (intrauterine growth retardation) rats. Two types of experimental IUGR were induced by maternal starvation and ligature of uterine vessels. On the 20th day of gestation polyamine levels in tissues were compared with untreated controls. In normal developing fetal liver the levels of putrescine and spermidine were higher than those in adult. In particular, the putrescine level on the 15th day of gestation was about 50 times higher than that in adult. In the neonatal period the increases in putrescine and spermidine were proceeding to those of nucleic acids. On the contrary, the spermine levels in fetal liver was not higher than in adult liver. In fetal brain, the levels of the three polyamines were higher than those in adult brain. In IUGR rats the results were characteristic in liver, namely, the putrescine level was significantly decreased, on the other hand, spermidine and spermine levels significantly increased compared with the untreated control levels. No significant changes in polyamine level were observed in brain. In placenta, only the spermine level was increased compared with the untreated control level. These results suggest that there is a close relationship between polyamine and fetal development, and putrescine may play an important role as the trigger in fetal development.