Lectin-induced deciduoma formation in the pseudopregnant rat

Decidual cell induction in the pseudopregnant rat was examined in this study using the lectin concanavalin A (ConA). The histochemical binding of the lectin to the uterine cell surface at the time of deciduomatic induction was also studied. ConA was found to induce significant deciduomata (decidual-like tissue) in the uterine horn when injected intraluminally on day 5 of pseudopregnancy (PSP). ConA-induced deciduomata appeared as a series of discrete nodules in the uterine horn, reminiscent of the anatomical appearance of normal embryo implantation sites. Deciduoma induction by ConA was greatly reduced by pre-absorption of the lectin with its competitive sugar. Lectin histochemistry revealed binding of ConA to the cell surface on day 5 of PSP. Pre-absorption of the lectin with its competitive sugar also significantly reduced surface binding of the lectin, and this finding may be correlated with the greatly reduced ability of the pre-absorbed lectin to induce deciduomata. Possible mechanisms for the induction of deciduomata by lectins are considered.