Lectin binding to normal human endometrium.

Avidin-biotin-peroxidase labelling technique was used to localize the binding sites of peanut agglutinin (PNA), Ulex europaeus (UEA-I), wheat germ agglutinin (WGA), concanavalin A (Con A), and Ricinus communis (RCA-I) in 30 samples of endometrium at different stages of the menstrual cycle and in early pregnancy. PNA and UEA-I exhibit weak binding to the apical portions of epithelial cells in proliferative and secretory phases, but become strongly positive in pregnancy. WGA and RCA-I show weak binding to glandular epithelium in the proliferative phase, but increase their affinity in the secretory phase. Con A demonstrates strong affinity to decidual cells.