The increased endotoxin-sensitivity of pregnant rats, as reflected by glomerular ecto-ADP-ase activity, is not dependent on the presence of decidual cells.

In the present study the possible role of decidual cells in the pregnancy-associated increased sensitivity of glomerular ecto-ADP-ase to endotoxin was investigated. Early (day 5) pregnant (E-Pr; n = 10), pseudopregnant (E-PSP; n = 10), (day 5), pseudopregnant rats with a decidualized uterus (E-DEC; n - 10), as well as late (day 14) pregnant (L-Pr; n = 10), pseudopregnant (L-PSP: n = 10) (day 14), and pseudopregnant rats with a decidualized uterus (E-DEC; n = 10) were infused with either endotoxin (1.0 mg/kg bw) or saline. Three days later rats were killed and specimens of the left kidney were snap-frozen. Cryostat kidney sections (4 microns) were stained for ecto-ADP-ase activity and quantitatively evaluated. The results show that only glomerular ecto-ADP-ase activity of both groups of pregnant rats (E-Pr and L-Pr) was significantly decreased after endotoxin infusion as compared to saline infusion. In the other groups of rats, no significant differences in ecto-ADP-ase activity were observed between saline and endotoxin infusion. It is concluded that decidual cells do not play a role in the increased sensitivity of ecto-ADP-ase to endotoxin during pregnancy.