Prostaglandin D2 synthase: a component of human amniotic fluid and its association with fetal abnormalities

Prostaglandin D2 (PGD2) synthase is responsible for PGD2 production in the brain. Western blot analysis of human amniotic fluid and probing with a polyclonal antibody against prostate-specific antigen (PSA) revealed a strong immunoreactive band with a molecular mass of 25 kDa. The immunoreactive species, which does not react with monoclonal anti-PSA antibodies, was purified to homogeneity from 1 L of amniotic fluid through successive cycles of gel filtration and ion-exchange chromatography. Amino acid sequence analysis (15 cycles) revealed that the protein was highly homologous or identical to PGD2 synthase. On semiquantitative analysis, PGD2 synthase concentration appears to increase dramatically during gestational weeks 12-25 and then declines slowly until term. PGD2 synthase concentration in amniotic fluid was altered in many abnormal pregnancies, most notably its decrease in trisomic fetuses and fetuses with renal abnormalities.