Abstract
Human endometrium possesses remarkable secretory properties and the characteristics
of a neuroendocrine organ. Epithelial cells of human endometrium express the corticotropin-releasing
hormone (CRH) and opioid peptide precursors genes (i.e., proopiomelanocortin, proenkephalin,
and prodynorphin) and their end products. Endometrial neuropeptides are under the
control of ovarian steroid hormones and locally produced prostanoids and cytokines.
Additionally, neuropeptides participate in local paracrine regulatory loops, facilitating
communication between endometrial epithelial and stromal cells as well as the interaction
between endometrial and myometrial cells. In view of the proinflammatory cytokine
properties of CRH, we postulate that endometrial CRH may participate in intrauterine
inflammatory and vascular processes associated with stromal cell decidualization and
blastocyst implantation. Additionally, given the myorelaxant actions of opioids these
endometrial neuropeptides may participate in the control of myometrial contractility.
Keywords:
Endometrium - opioids - CRH - implantation - decidualization
