Human uterine and placental arteries exhibit tissue-specific acute responses to 17β-estradiol and estrogen-receptor-specific agonists.

The discrete regulation of vascular tone in the human uterine and placental circulations is a key determinant of appropriate uteroplacental blood perfusion and pregnancy success. Humoral factors such as estrogen, which increases in the placenta and maternal circulation throughout human pregnancy, may regulate these vascular beds as studies of animal arteries have shown that 17β-estradiol, or agonists of estrogen receptors (ER), can exert acute vasodilatory actions. The aim of this study was to compare how acute exposure to ER-specific agonists, and 17β-estradiol, altered human placental and uterine arterial tone in vitro.

Differential effect of insulin like growth factor-I on constriction of human uterine and placental arteries.

Context: Discrete regulation of the uterine and placental vasculatures is an important feature of uteroplacental perfusion and pregnancy success because appropriate maternal/fetal exchange of nutrients and gases is crucial for normal fetal growth. Placental vasculature lacks autonomic innervation so tone is controlled by locally derived vasoactive factors. IGF-I, which is produced by the placenta, is critical for normal fetal growth and studies of animal vascular systems have shown that IGF-I regulates vasomotor tone.