Prostaglandin metabolism in umbilical vessels of smoking and non-smoking mothers.

Arachidonic acid (AA) and its metabolites are responsible for the regulation of the umbilical blood flow. We investigated the prostaglandin (PG) synthesis in umbilical arteries and veins of 16 smoking and 17 non-smoking mothers. AA and PGs were analyzed after extraction of samples by means of thin layer chromatography (TLC). Of all the AA metabolites in umbilical arteries and veins, prostacyclin reached the highest concentration. In non-smoking mothers the conversion rate of AA in arteries and veins was similar. The only exception was PGE2 which showed a significantly lower concentration in umbilical veins of smoking mothers. However, the influence of PGE2 on the blood flow of umbilical arteries and veins seems to be of minor importance compared to other vessels.