Human endometrium expresses urocortin II and III messenger RNA and peptides

Urocortin II and urocortin III are recently identified corticotropin-releasing factor-related neuropeptides, and their endometrial expression throughout the menstrual cycle and in early pregnancy was evaluated in the present study by semiquantitative reverse transcriptase polymerase chain reaction and immunohistochemistry. The endometrial expression of urocortin II mRNA was significantly (P<.01) higher in the early proliferative phase of the menstrual cycle than in other phases and maternal decidua (MD), whereas that of urocortin III mRNA was higher (P<.01) in MD than in all other endometrial samples. Both peptides were immunolocalized in epithelial, stromal, and endothelial cells.