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Scientists have linked the rise in a
naturally occurring chemical found in the blood with preeclampsia,
a pregnancy complication marked by high blood pressure,
swelling in the legs and other symptoms.
The complication
affects as many as 1
in 10 first pregnancies.
If left untreated, preeclampsia can
develop into eclampsia, a life-threatening
condition in which a woman has convulsive seizures
in late pregnancy or during the first week after delivery.
Researchers demonstrated for the first
time that levels of S-nitrosoalbumin,
a chemical found in blood, are significantly elevated in
women with preeclampsia.
Normally, the body uses naturally produced
nitric oxide (NO) to help keep blood vessels relaxed, which
helps keep blood pressure in check. In an effort to keep
NO readily available, the body keeps a reserve of the chemical
in the blood in the form of another chemical called S-nitrosoalbumin.
The women with preeclampsia were found
to have levels of S-nitrosoalbumin that were 2 to 3 times
higher than those of the other study participants.
In addition, women
with preeclampsia also had low levels of vitamin C
in their blood. Normally, vitamin C helps break down the
S-nitrosoalbumin to release nitric oxide into the bloodstream.
Researchers speculate that the connection
between low vitamin C and high S-nitrosoalbumin levels is
important for preeclampsia, as it implies that the amounts
of usable NO that are necessary for proper control of vascular
relaxation are not sufficient.
Circulation
Research June 8, 2001;88
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