The Functional Role of the Renin-Angiotensin System in Preeclampsia

The renin-angiotensin system (RAS) is a signaling pathway that acts as a major regulator in human physiology. To sidestep the major intimidations of low blood volume and low blood pressure, the diverse actions of Ang II/ACE/AT(1)R can be viewed as a useful response in maintaining homeostasis. The deleterious action of the Ang II/ACE/AT(1)R axis is endogenously counterbalanced by ACE 2/Ang 1-7/MasR. Yet, over activation of the Ang II/ACE/AT(1)R axis may lead to hypertension. Preeclampsia is characterized by hypertension with proteinuria or end-organ dysfunction after 20 weeks of gestation. The early-onset sort is more genuine and capable of high maternal and fetal dismalness and mortality rates than the late-onset sort of preeclampsia. Various theories for the pathogenesis of preeclampsia are, the exact underlying molecular mechanisms remain unclear but are likely to be multifactorial. Later studies of RAS in preeclampsia have highlighted the need for thorough research on this topic. There is an increase in the levels of circulating angiotensinogen during the first 20 weeks of gestation. At the beginning of the pregnancy, there is an increment of prorenin by 4 - 5 times. Renin synthesis in preeclampsia is suppressed. PE pregnant women have higher levels of prorenin receptor expression in their placental tissue than normal pregnant women. AT1 receptor autoantibodies are also observed. Ang II is raised in normal pregnancies as a result of higher levels of angiotensinogen and renin. Preeclampsia causes a decrease in angiotensin-(1-7) levels. Aldosterone is also relatively low in pregnancies complicated by preeclampsia.