Endometrial Decidualization Does Not Trigger the Blood Pressure Decline of Normal Early Pregnancy in Mice

ABSTRACT A drop in mean arterial pressure (MAP) characterizes early, normal pregnancies of humans and of inbred mice, species with hemochorial placentation. Murine MAP, assessed by continuous radiotelemetry, falls from implantation to Gestation Day 9 (GD9) and then recovers. The change in the trajectory of mouse MAP after GD9 coincides with full maturity of the placenta and onset of its circulation. To identify whether these early gestational changes in hemodynamic function are conceptus and/or maternally regulated, pseudopregnancy (conceptus absent) with endometrial decidualization was established in radio transmitter-implanted, randomly bred CD1 mice. To avoid destabilization of MAP by anesthesia and surgery, decidualization was induced by transcervical infusion of concanavalin A-coated Sepharose beads 48 h after the female had copulated with a vasectomized male. In comparison to the postimplantation drop in MAP recorded in CD1 females mated by fertile males, pseudopregnancy MAP was stable to Gestation-...