Placental corticotropin-releasing factor. An update

Area of Science:

• Reproductive endocrinology
• Maternal-fetal medicine

Background:

• Corticotropin-releasing factor (CRF) plays local and endocrine roles during pregnancy.
• Urocortin, a related peptide, is found in the human placenta and membranes.
• CRF and urocortin influence intrauterine tissues, including myometrial contractility and prostaglandin release.

Purpose of the Study:

• To investigate the role of CRF and its related peptides in human pregnancy and parturition.
• To examine the expression and function of CRF and urocortin in placental tissues and their impact on maternal and fetal physiology.

Main Methods:

• Localization studies of CRF, urocortin, and CRF-BP in placental and membrane tissues.
• Measurement of plasma CRF and CRF-BP levels in pregnant women at different gestational stages and in cases of preterm labor.
• Assessment of CRF's effects on placental vasculature and fetal adrenal steroidogenesis.

Main Results:

• CRF is present in the placenta, decidua, and myometrium, influencing local contractility and prostaglandin release.
• Urocortin mimics CRF's local effects, impacting ACTH and prostaglandin release and myometrial contractility.
• CRF levels increase during pregnancy, peaking at term, while CRF-BP levels decrease. High CRF and low CRF-BP are observed in preterm labor.

Conclusions:

• The CRF system, including CRF and urocortin, is intricately involved in regulating pregnancy and the timing of parturition.
• Aberrant levels of CRF and CRF-BP are associated with preterm labor, suggesting a role in the parturition pathway.
• CRF influences placental vasculature and fetal adrenal function, highlighting its systemic effects during pregnancy.