Identification of urocortin mRNA and peptide in the human endometrium

Urocortin is a 40-amino acid peptide belonging to the corticotropin-releasing factor (CRF) family. In human reproductive tissues, urocortin expression has previously been demonstrated in the ovary, placenta fetal membranes and in pregnant uterine tissues, while no data are available on the expression of the peptide in the nonpregnant uteri-is. In this study urocortin expression was evaluated by both immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR), in human uterine tissues and cells at different phases of the menstrual cycle. Urocortin was immunolocalized in endometrial epithelial and stromal cells, as well as in the myometrium, and in vascular smooth muscle cells. No differences between proliferative and secretory phase were observed. These results were confirmed by PT-PCR analysis of isolated endometrial epithelial and stromal cells, and myometrial specimens. These findings open ne,v questions Oil the roles played by urocortin in the human uterus.