Is human decidua a specialized endocrine organ?

Area of Science:

• Reproductive Endocrinology
• Maternal-Fetal Physiology

Background:

• The human placenta, amnion, chorion, and decidua capsularis produce protein hormones.
• The specific endocrine role of the decidua capsularis in hormone release remains to be fully elucidated.

Purpose of the Study:

• To investigate the in vitro production and release of protein hormones, particularly prolactin (PRL), by human decidua capsularis.
• To determine if the decidua capsularis is a specialized endocrine structure for PRL release.

Main Methods:

• Incubation of human placental, amniotic, chorionic, and decidual tissues in vitro.
• Measurement of prolactin (PRL), chorionic somatomammotropin, human chorionic gonadotropin (CG), and growth hormone (GH) in the incubation medium.
• Inclusion of puromycin and bromocriptine in incubation media to assess PRL synthesis and receptor activity.

Main Results:

• Decidua capsularis showed a significant increase in PRL release during incubation, while placenta and amnion did not.
• Placenta exhibited rapid increases in chorionic somatomammotropin and CG, but not GH.
• Puromycin reduced decidual PRL content and release, and bromocriptine did not affect decidual PRL release, suggesting a lack of dopamine receptors.

Conclusions:

• The decidua capsularis demonstrates a specific endocrine function, primarily for PRL release.
• Decidual PRL-secreting cells likely lack dopamine receptors, consistent with in vivo findings.
• These findings support the decidua capsularis as a specialized endocrine structure within the human placenta.