ANTI-MAC-1 ANTIBODIES AND EARLY-PREGNANCY LOSS IN MICE

This study focused on the role of adhesion molecules in early pregnanc y in mice. Injection of anti-Mac-1 antibodies during early pregnancy r esulted in early pregnancy loss (only 30.7% of mice in the group injec ted with anti-Mac-1 antibody were pregnant compared with 87.5% of cont rols), while mice treated with anti-Mac-1 antibodies during late pregn ancy did not show a significant abortive effect (68.8% mice in the tre ated group were pregnant compared with 92.9% of control mice). Anti-LF A-1 alpha, LFA-1 beta or mouse Ag-Eb antibodies, when injected during early pregnancy, caused a nonsignificant decrease in pregnancy rate ra nging between 15% and 25% (P > 0.05), while anti-Thy-1.2 antibodies de monstrated a marginal effect only. Staining of uterine tissue sections , collected on days 4-6 of pregnancy, with anti-Mac-1 antibodies, demo nstrated antibody bound to cells in the deep endometrium and in the my ometrium but not in the uterine area close to the lumen or on the surf ace of the blastocyst. These results indicate a possible role for the Mac-1 in early pregnancy.