[Developmental changes in taurine and other sulfur-containing amino acid concentrations in fetal and neonatal rats]

The concentrations of taurine and other sulfur-containing amino acids in the fetal, neonatal and maternal liver, placenta, and whole fetal body between the 15th day of gestation and the 14th day after birth were determined using an automatic amino acid analyzer. In the fetal liver and placenta, the taurine concentration was the highest among all ninhydrin positive compounds. In these tissues the concentration of taurine increased significantly with the number of gestational days. Moreover, the total amount of taurine per fetus increased markedly up to term after the 15th day of gestation, and reached almost the same value as the total amount for adult rat liver. A striking difference in the changes in taurine concentrations during gestation between the fetal and maternal rat liver was observed: In contrast to the increase in the fetal liver, a significant decrease in the maternal liver was observed near term. But in these organs, no significant change in methionine, cystathionine and cysteine concentrations was observed during the perinatal period. These results suggest that taurine is supplied to the developing rat fetus from the maternal liver throughout gestation.