Platelet-activating factor-acetylhydrolase activity in normotensive and hypertensive pregnancies.
OBJECTIVE
The purpose of our study was to evaluate the hypothesis that pregnancy is associated with decreased platelet-activating factor-acetylhydrolase activity in women with normotension, but not in women with hypertension.


METHODS
We evaluated plasma platelet-activating factor-acetylhydrolase activity in normal nonpregnant women (n = 10), normal pregnant women (n = 24), pregnant women with pregnancy-induced hypertension-preeclampsia (n = 7), and a group of men with normotension (n = 10).


RESULTS
Platelet-activating factor-acetylhydrolase activity was lower at 32 weeks of gestation during normal pregnancies compared with nonpregnant controls (p < 0.001); however, in women with pregnancy-induced hypertension-preeclampsia, platelet-activating factor-acetylhydrolase activity was not decreased. Platelet-activating factor-acetylhydrolase activity in men was higher than in all women (p < 0.01).


CONCLUSIONS
Pregnant women with normotension may be refractory to pressor agents such as angiotensin II in part because of the decrease in plasma platelet-activating factor-acetylhydrolase activity, which results in an increase in platelet-activating factor. In contrast, enzyme activity is not decreased in pregnant women with hypertension, who have increased sensitivity to various pressor agents.
Maki
N
N
Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas 75235-9051.
Magness
R R
RR
Miyaura
S
S
Gant
N F
NF
Johnston
J M
JM
D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase; D000328:Adult; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000201:enzymology*; D008297:Male; D010741:Phospholipases A / Q000097:blood*; D011247:Pregnancy / Q000097:blood*; D011249:Pregnancy Complications, Cardiovascular / Q000097:blood / Q000201:enzymology*
D010741:Phospholipases A; D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase