AT₁ receptor heterodimers and angiotensin II responsiveness in preeclampsia

Abstract 

Preeclampsia is a pregnancy-specific hypertensive disorder with unknown etiology, which affects 5% to 10% of all pregnancies. Increased sensitivity to the vasoconstrictor angiotensin II is a common feature of preeclampsia, although underlying mechanisms are barely understood. Recent data reveal a potential mechanism for the increased angiotensin II responsiveness in preeclampsia: increased levels of heterodimers between the vasopressor receptor AT₁ and the vasodepressor receptor B₂. The receptor heterodimers display increased sensitivity toward angiotensin II and are found in platelets and in omental vessels of preeclamptic women. Moreover, AT₁/B₂ receptor heterodimers are resistant to inactivation by reactive oxygen species, which is elevated in normal and preeclamptic pregnancies. Thus, a major symptom of preeclampsia is the result of complex formation between two G-protein-coupled receptors.