Fig. 4.

Dysregulation of endothelin receptor subtype B (ET_BR) contributes to exaggerated vasoconstrictor tone in women who have had preeclampsia. Compared with women who had a healthy pregnancy (HC), women who had preeclampsia (PrEC) have an exaggerated vasoconstriction response to endothelin (ET-1, 10⁻⁸ M) measured in the cutaneous microvasculature. Coinfusion of the ET_BR-antagonist BQ-788 augments vasoconstriction in HC, demonstrating the vasodilatory role of ET_BR in healthy premenopausal women. However, coinfusion of BQ-788 attenuates the vasoconstriction response in PrEC, suggesting that ET_BR contributes to constriction in women who have had preeclampsia. ET_BR-mediated dilation, measured as the increase in cutaneous conductance during coinfusion of the ET_AR-antagonist BQ-123, was attenuated in PrEC compared with HC. *P < 0.05 vs. HC; ‡P < 0.05 vs. ET-1 alone within group. These data demonstrate that dysregulation of the ET_BR contributes to microvascular dysfunction in women who have had preeclampsia. Adapted with permission of Portland Press, from Stanhewicz et al., Clin Sci (Lond) 131: 2777–2789, 2017 (83).