Physiological and pathophysiological roles of placental aminopeptidase in maternal sera: possible relation to preeclampsia and preterm delivery.

BACKGROUND: Both preeclampsia and preterm delivery are important complications in pregnancy and are still diseases of unknown causes, despite considerable research in recent times. These complications constitute obstetric emergencies that require expert knowledge and management skills.

OBJECTIVES: This article reviews the emerging role of aminopeptidases in the monitoring and development of improved therapeutic strategies that provide better patient selection for therapeutic personalization.

METHODS: A literature review (PubMed, Medline) to the present.

RESULTS/CONCLUSION: The fetus produces angiotensin II, vasopressin and oxytocin, which are highly vasoactive and uterotonic, and these peptides increase in parallel with fetal growth and in response to stressors such as hypoxia. Because these hormones are small molecules, it is probable that there occurs the leak out of these hormones from the feto-placental unit. Oxytocinase and angiotensinase in human placenta are identical to placental leucine aminopeptidase and aminopeptidase A, respectively. They work as barriers of peptide hormones between fetus and mother and their activities in pregnancy sera increase with advancing gestation. Aminopeptidase activities in maternal sera might be useful for monitoring of preeclampsia and predicting the prognosis of preterm delivery.