IMMUNOHISTOCHEMICAL LOCALIZATION OF THE GLUCOCORTICOID RECEPTOR IN HUMAN FETAL MEMBRANES AND DECIDUA AT TERM AND PRETERM DELIVERY

The human fetal membranes and decidua may be important in the onset an d/or progression of human labor by providing prostaglandins for this p rocess. Glucocorticoids have been implicated in the regulation of pros taglandin production by these tissues but to date there is no direct e vidence for glucocorticoid receptors (GRs) being present in human intr auterine tissues. The purpose of the present study was to determine, u sing immunohistochemistry, whether the human fetal membranes and decid ua contained GRs; to determine the localization of receptors to the cy toplasm or nuclei, and to examine the content and distribution of the GRs in tissues obtained during pregnancy following preterm labor (<37 weeks) and at term prior to and following term labor. Term tissues wer e obtained prior to labor by elective Cesarian section (n=9) Or follow ing vaginal delivery (n=9). Tissues from 14 patients who delivered pre term but with no clinical evidence of infection were also examined. Cr yostat sections were thaw-mounted onto microscope slides. The immunore active GRs were visualized with an Elite Vectastain ABC Kit using a po lyclonal antibody prepared against a synthetic peptide corresponding t o amino acids 346-367 of the human GR. At term, nuclear GRs were found in amnion epithelial cells, mesenchyme and the chorion laeve. GRs wer e present, but were less defined, in the decidua. A similar distributi on was found in the preterm tissues. However, nuclear staining in the amnion epithelial cells, mesenchymal cells, chorion and decidua was mo re pronounced in tissues obtained following preterm labor. This study provides direct evidence for the presence of GRs in human fetal membra nes and decidua, and suggests the possible importance of multiple cell types in the action of glucocorticoids in these tissues.