Monoamine-oxidizing enzymes in human pregnancy

Area of Science:

• Biochemistry
• Reproductive Biology
• Enzymology

Background:

• Benzylamine oxidase (BzAO) and monoamine oxidase (MAO) enzymes play crucial roles in biological processes.
• Understanding their activity during pregnancy is essential for maternal and fetal health.
• Previous studies have indicated differential distribution and activity of these enzymes in various tissues.

Purpose of the Study:

• To investigate the activity of BzAO in human maternal blood throughout gestation, parturition, and puerperium.
• To compare BzAO and MAO A/B activities in amniotic fluid, placenta, and umbilical and placental vessels.
• To explore the potential physiological implications of these enzymatic activities during pregnancy.

Main Methods:

• Assay of BzAO activity in maternal plasma at different gestational stages.
• Enzymatic assays for BzAO, MAO A, and MAO B in amniotic fluid, placenta, and vascular tissues.
• Statistical analysis to determine correlations and significant variations.

Main Results:

• Maternal plasma BzAO activity showed significant variations by the end of the first trimester, at parturition, and postpartum.
• No correlation was observed between maternal BzAO levels and fetal growth.
• BzAO was predominant in amniotic fluid and vascular tissues, while MAO A was predominant in the placenta; MAO A was undetectable in amniotic fluid.
• Placental vessels exhibited higher MAO A activity than umbilical vessels.
• BzAO and soluble MAO B were detected in amniotic fluid.

Conclusions:

• Maternal BzAO activity undergoes dynamic changes during pregnancy and the postpartum period.
• The distinct distribution of BzAO and MAO A/B in placental and fetal tissues suggests specific roles during gestation.
• The presence of BzAO and MAO B in amniotic fluid warrants further investigation into their physiological functions.