Researchers at the University of Manchester and Manchester University NHS Foundation Trust identified a major defect in microvascular regulation in women with pre-eclampsia. The breakthrough sheds new light on why blood pressure rises so dramatically in the condition and could point towards entirely new ways of treating it.
Pre-eclampsia affects 2–8% of pregnancies worldwide and is linked to serious complications including stroke, organ damage, premature birth and stillbirth. At present there is no cure other than delivering the baby and placenta, often forcing doctors to perform earlier deliveries.
But now the researchers have identified a key failure in the way small arteries regulate blood flow in women with the condition.
The team recruited patients at Saint Mary’s Hospital (SMH), part of MFT, and compared tiny arteries from pregnant women with and without preeclampsia. The researchers discovered that a vital natural relaxation mechanism was severely disrupted in those with the disease.
The vessels were taken from the omentum – a fold of fatty tissue inside the abdomen that helps protect and support the abdominal organs – and placed under pressure in a laboratory to study their functioning.
They found that microscopic calcium sparks (which normally signal arterial smooth muscle to relax) were reduced by up to 75% at physiological pressures. Calcium stores were depleted and less able to refill, impairing the pressure-balancing mechanism and contributing to vasoconstriction and hypertension.
The immune peptide HBD2 did not restore the sparks but still relaxed vessels via an alternative pathway component. This suggests potential therapies that bypass the defective mechanism to control maternal blood pressure, prolong pregnancy and reduce early delivery.
Study lead Dr Stephanie Worton (University of Manchester; Honorary Consultant in Obstetrics, Maternal and Fetal Health Research Centre, Saint Mary’s) stated this is the first demonstration of a profound impairment in this calcium signalling pathway, while vessels remain relaxable via alternative routes. While these are promising, there is further work needed on drug development for pregnancy.
Source: NHS Manchester University
