EDN1 and preeclampsia: In women with preeclampsia, vasoconstrictor ET-1 levels are increased.29 One study on microvascular dysfunction found that ET-1-mediated vasoconstriction was increased in the microvasculature of women with a history of preeclampsia.30 This may be attributed to the absence of ET-1 receptor type-B-mediated dilation, leading to an exaggerated vasoconstrictive response to ET-1.30