Differential distribution of glycoconjugates in human reproductive tract

Objectives: To study the distribution of glycoconjugates in the epithelia of various regions of the human female reproductive tract and to examine whether lectins can be used as specific probes to define cell populations in the human female reproductive tract. Design: Nineteen fluorescein isothiocyanate (FITC)-labeled lectins, which recognize different oligosaccharide structures, were applied to frozen sections of human fallopian tubes (distal and proximal segments) and endometrium. The differential binding patterns of the lectins to the epithelia were evaluated under fluorescent microscopy. Results: Four of 19 FITC-labeled lectins tested demonstrated distinct binding patterns along the reproductive tract. Arachis hypogaea (PNA) and Ricincus communis II selectively reacted with epithelial cells of endometrium and distal, but not proximal tube. In addition, PNA distinguished ciliated from secretory cells of the distal tube. Maclura pomifera binding followed a gradient of decreasing intensity from distal to proximal tube and was negative in the endometrium. Dolichos biflorus reacted exclusively with proximal tubal epithelium. Conclusions: Analysis of the FITC-lectin binding pattern and the sugar specificities indicate that the distribution of galactosyl residues varies among different regions of the reproductive tract, whereas glucosyl, mannosyl and fucosyl residues are more evenly distributed. The differential expression of glycoconjugates may be involved in the distinct biological function of each region in female reproductive tract.