August 31, 2001 WASHINGTON (AP) - Researchers studying eclampsia, a dangerous condition in pregnant women, have found a clue to the big jump in blood pressure that accompanies it.
Their findings may lead to earlier diagnosis of pre-eclampsia, which precedes the condition. Eclampsia causes seizures and can force early delivery of the baby, sometimes endangering the lives of both mother and child.
The scientists, led by Dr. Ursula Quitterer of the Pharmacology and Toxicology Institute in Wuerzburg, Germany, studied platelets, small disc-shaped blood cells, to analyze the condition of pregnant women. They looked at platelets from 34 women, 19 of whom had pre-eclampsia.
In the platelets from the women with pre-eclampsia, two normally separate receptors on the surface of the cells were fused together. These receptors respond to different chemicals in the bloodstream - angiotensin II, which causes blood vessels to narrow, and bradykinin, which counters the effect of angiotensin.
These combined receptors result in the women becoming hypersensitive to angiotensin, Quitterer explained. That leads to the jump in blood pressure.
As a result of this finding, she said, a research program is being launched to develop ways to make an early diagnosis of pre-eclampsia, based on the presence of this combined, or fused, receptor.
In addition to the increase in blood pressure, pre-eclampsia can also be marked by swelling, weight gain and protein in the urine. It occurs in about 5 percent of pregnant women and the cause is unknown.
The findings are reported in Friday's issue of the journal Nature Medicine.
Dr. David Lodwick of the University of Leicester in England noted in a commentary on the findings that, in addition to raising blood pressure, angiotensin II also stimulates the nervous system.
He concluded that the findings "provide a plausible explanation for hypertension in pre-eclampsia."
Working with Dr. Quitterer were Heinz Lother, also of the Institute in Wuerzberg, and Said AbdAlla and Adel el Massiery of Ain Champs University Hospital, Cairo, Egypt.
Copyright 2001 The Associated Press. All rights reserved.
