Vasodilator may improve blood vessel dysfunction in women who had preeclampsia

USA: Increasing the bioavailability of vasodilator Angiotensin (1-7) may reduce blood vessel dysfunction in postpartum women who have had preeclampsia, finds a recent study published in the American Journal of Physiology.

Preeclampsia is a pregnancy complication characterized by high blood pressure (BP), protein in the urine and severe swelling in the mother. It occurs in up to 10 per cent of pregnancies. Angiotensin 1-7 (ang 1-7) is an endogenous inhibitor of the actions of angiotensin II -- a synthetic vasoconstrictor used for the treatment of hypotension. Ang 1-7 plausible druggable targets in women who had preeclampsia.

Anna E. Stanhewicz and Lacy M. Alexander from the US examined the therapeutic potential of ang 1-7 in the microvasculature of women with a history of preeclampsia (PrEC, n=13) and parity matched healthy control women (HC, n=13) hypothesizing that administration of ang 1-7 would increase endothelium-dependent dilation and NO-dependent dilation, and decrease ang II-mediated constriction in PrEC.

Endothelium-dependent vasodilator function was assessed using the cutaneous microcirculation in response to graded infusion of acetylcholine in control sites and sites treated with L-NAME (NO-synthase inhibitor), ang 1-7, or L-NAME + ang 1-7. Vasoconstrictor function was measured in responses to ang II in control sites and sites treated with ang 1-7.

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Key findings of the study include:

• PrEC had reduced endothelium-dependent dilation and NO-dependent dilation (P=0.04 vs. HC).


• Ang 1-7 co-infusion augmented endothelium-dependent dilation and NO-dependent dilation in PreEC but had no effect in HC.


• PrEC demonstrated augmented vasoconstrictor responses to ang II (P<0.01 vs HC), that was attenuated by co-infusion of Ang 1-7 co-infusion.


• Ang 1-7 increased endothelium-dependent vasodilation via NOS-mediated pathways and attenuated ang II-mediated constriction in women who have had preeclampsia.

"Our findings suggested that ang 1-7 may be a viable therapeutic target for improved microvascular function in women who have had a preeclamptic pregnancy," concluded the authors.

The study, "Local Angiotensin 1-7 Administration Improves Microvascular Endothelial Function in Women Who Have Had Preeclampsia," is published in the American Journal of Physiology.

DOI: https://doi.org/10.1152/ajpregu.00221.2019