Isolated microparticles, but not whole plasma, from women with preeclampsia impair endothelium-dependent relaxation in isolated myometrial arteries from healthy pregnant women.
OBJECTIVE
This study was performed to establish whether microparticles from plasma of women with preeclampsia cause endothelial dysfunction, as described for isolated myometrial arteries in preeclampsia.


METHODS
Myometrial arteries were isolated from biopsy specimens obtained at cesarean delivery from healthy pregnant women (n = 22) and mounted in a wire myograph. Bradykinin concentration-response curves were obtained before and after 1-hour incubation or after overnight incubation with one of the following preparations of plasma from individual women with preeclampsia (n = 16): Whole plasma, microparticle-free plasma, isolated microparticles resuspended in physiologic saline solution or physiologic saline solution. Overnight incubation was also performed with microparticles isolated from healthy pregnant women (n = 6). One-hour incubation was performed with 2% or 10% solution and overnight incubation with 5% solution.


RESULTS
No effect of preeclamptic plasma, with or without microparticles, on bradykinin-mediated relaxation was observed. Overnight, but not 1-hour, incubation with preeclamptic microparticles caused abolishment of bradykinin-mediated relaxation in contrast to healthy pregnant microparticles (P <.005).


CONCLUSIONS
Preeclamptic microparticles, but not healthy pregnant microparticles cause endothelial dysfunction in isolated myometrial arteries from healthy pregnant women after overnight incubation, whereas other preeclamptic plasma constituents protect the endothelium from this effect.
Vanwijk
Marja J
MJ
Departments of Obstetrics and Gynecology, Academic Medical Center, Amsterdam, The Netherlands. M.J.VanWijk@AMC.UVA.NL
Svedas
Eimantas
E
Boer
Kees
K
Nieuwland
Rienk
R
Vanbavel
Ed
E
Kublickiene
Karolina R
KR
D000328:Adult; D001158:Arteries / Q000503:physiopathology*; D001706:Biopsy; D001920:Bradykinin / Q000494:pharmacology; D002585:Cesarean Section; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000503:physiopathology; D009215:Myometrium / Q000098:blood supply*; D011225:Pre-Eclampsia / Q000097:blood*; D011247:Pregnancy; D012016:Reference Values; D014661:Vasoconstriction; D014667:Vasopressins / Q000494:pharmacology
D014667:Vasopressins; D001920:Bradykinin