Calcium modulation of endothelium-derived prostacyclin production in ovine pregnancy.

  title={Calcium modulation of endothelium-derived prostacyclin production in ovine pregnancy.},
  author={Ronald R. Magness and Charles R. Rosenfeld},
  volume={132 6},
Refractoriness to angiotensin-II (ANG II)-induced vasoconstriction is greater in the uteroplacental vs. systemic vascular beds during pregnancy, possibly reflecting enhanced uterine artery prostacyclin production. We determined the role(s) of calcium and calcium channels in regulating basal and ANG II-induced vascular prostacyclin production in uterine and omental (systemic) arteries obtained from pregnant (P) and nonpregnant (NP) ewes. To evaluate the endothelial contribution to basal and… 
Pregnancy Induces an Increase in Angiotensin II Type-1 Receptor Expression in Uterine But Not Systemic Artery Endothelium1.
It is hypothesized that the increase in uterine artery PGI2 production in response to AII in pregnancy is associated in part with a concomitant increase in AT1-R expression in uterin artery endothelium.
Angiotensin II regulation of ovine fetoplacental artery endothelial functions: interactions with nitric oxide
Data from the laboratories suggest that elevations of the known vasoconstrictor Ang II in the fetal circulation may indeed play a role in the marked increases in fetoplacental angiogenesis and that Ang II‐elevated endothelial NO production may partly attenuate Ang II-induced vasconstriction on vascular smooth muscle.
Endothelial Vasodilator Production by Uterine and Systemic Arteries. IV. Cyclooxygenase Isoform Expression During the Ovarian Cycle and Pregnancy in Sheep1
COX-1 expression is specifically up-regulated in the uterine artery endothelium during high uterine blood flow states such as the follicular phase and, in particular, pregnancy.
Mechanisms regulating angiotensin II responsiveness by the uteroplacental circulation.
  • C. Rosenfeld
  • Medicine, Biology
    American journal of physiology. Regulatory, integrative and comparative physiology
  • 2001
Systemic pressor responses to infused ANG II are attenuated in normotensive pregnancies and the uteroplacental vasculature is even less sensitive, suggesting development of mechanisms to maintain basal UBF and permit the rise in UBF necessary for fetal growth and well-being.
Prostaglandin I2 mediates weak vasodilatation in human placental microvessels
It is shown that placental endothelial PGI2 does not markedly contribute to vascular dilation in the human placenta, in notable contrast to non-PVs, which may be helpful for further investigations of potential targets in the treatment of diseases such as preeclampsia.
Cyclooxygenase-dependent mechanisms mediate in part the anti-dilatory effects of perivascular adipose tissue in uterine arteries from pregnant rats
It is hypothesized that uterine PVAT modulates the balance between the contribution of nitric oxide synthase (NOS)- and cyclooxygenase (COX)-dependent pathways to acetylcholine (ACh)-induced relaxation in isolated uterine arteries.
Pregnancy and ovarian steroid regulation of angiotensin II type 1 and type 2 receptor expression in ovine uterine artery endothelium and vascular smooth muscle.
The net effect of pregnancy may be an increase in the AT1R/AT2R ratio in both UA Endo and VSM but through apparently distinct mechanisms, which is similar to the luteal state for AT1r and AT2R expression, while the E2beta-primed model does not resemble the nonpregnant or pregnant state.


Evidence that prostacyclin modulates the vascular actions of calcium in man.
A new vascular regulatory system in which PGI2 modulates the systemic and renal vascular actions of calcium in man is indicated, suggesting that calcium entry and not alpha 1 receptor activation mediates Ca++ pressor and P GI2 stimulatory effects.