Microparticles from preeclamptic women induce vascular hyporeactivity in vessels from pregnant mice through an overproduction of NO (original) (raw)
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The American Journal of Pathology, 2006
We investigated the role of microparticles in vascular dysfunction of the multisystemic disorder of preeclampsia in women's omental arteries or mouse arteries. Preeclamptic women displayed increased circulating levels of leukocyte-and platelet-derived microparticles compared with healthy pregnant individuals. Microparticles from preeclamptic, but not healthy, pregnant women induced ex vivo vascular hyporeactivity to serotonin in human omental arteries and mouse aortas. Hyporeactivity was reversed by a nitric-oxide (NO) synthase inhibitor and associated with increased NO production. In the presence of a cyclooxygenase (COX)-2 inhibitor, serotonin-mediated contraction was partially reduced in arteries treated with healthy microparticles but was abolished after treatment with preeclamptic microparticles. This was associated with increased 8-isoprostane production. Preeclamptic microparticles induced up-regulation of inducible nitric-oxide synthase and COX-2 expression, evoked nuclear factor-B activation, and enhanced oxidative and nitrosative stress. Interestingly, the microparticles originating most probably from leukocytes were responsible for the COX-2 vasoconstrictor component of preeclamptic microparticles, whereas those of platelet origin were mainly involved in NO release. Moreover, vascular hyporeactivity was observed in arteries taken from mice treated in vivo with preeclamptic microparticles. This study demonstrates pathophysiological relevance and provides a paradoxical effect of preeclamptic microparticles associated with proinflammatory properties on vessels, leading to enhanced NO and superoxide anion levels and counteraction of increased COX-2 metabolites.
Life Sciences, 2002
Late pregnancy in rats is characterized by a decrease in arterial pressure and in isolated arterial vessels response to vasoconstrictors. In uterine arteries the pregnancy-associated attenuation of the response to vasoconstrictors has been attributed to an increase in basal and agonist-induced endothelial NO production. However, the role of NO in pregnancy-associated changes of systemic arteries reactivity to vasoactive agents remains to be fully elucidated. We examined whether pregnancy influences the reactivity of systemic arteries to vasodilator or vasoconstrictor agents through NOdependent mechanisms. Thoracic aortic rings and mesenteric arterial bed of late pregnant rats showed refractoriness to phenylephrine-induced vasoconstriction that was abolished by NO synthase inhibition. The potency of L-NNA to enhance tension of aortic rings preconstricted with phenylephrine (10 -20% of their maximal response) was significantly lower in preparations from pregnant animals. In phenylephrine-contracted aortas and mesenteric bed, the effects of the endothelium-dependent vasodilators acetylcholine, A23187 and bradykinin, were not influenced by pregnancy. Similarly, pregnancy did not affect the vasodilator responses of adenosine, isoproterenol, capsaicin, nitroprusside, forskolin, and Hoe234 in the mesenteric bed. NO synthase activity measured by determining the conversion of LÀ[ 3 H]-arginine to LÀ[ 3 H]-citrulline in aorta and mesenteric arteries homogenates was not altered by pregnancy. These findings show that endothelial-dependent and -independent vasodilators action as well as NO synthase activity in systemic arteries is uninfluenced by pregnancy, whereas pregnancyassociated hyporeactivity of systemic arteries to vasoconstrictors is related to an enhanced endothelial 0024-3205/02/$ -see front matter D 2002 Elsevier Science Inc. All rights reserved. PII: S 0 0 2 4 -3 2 0 5 ( 0 2 ) 0 1 5 7 6 -X (M.C.O. Salgado).
Endothelial microparticles and the antiangiogenic state in preeclampsia and the postpartum period
American Journal of Obstetrics and Gynecology, 2012
OBJECTIVE(S)-To determine if endothelial microparticles (EMPs), markers of endothelial damage, are associated with soluble fms-like tyrosine kinase 1 (sFlt1), soluble endoglin (sEnd), and placental growth factor (PlGF) in women with preeclampsia. STUDY DESIGN: A prospective cohort study was conducted on 20 preeclamptic women and 20 controls. EMP's measured by flow cytometry, sFlt1, sEnd, and PlGF were measured at time of enrollment, 48 hours, and 1 week postpartum. RESULTS-Preeclamptic CD31+/42−, CD 62E+, and CD105+ EMP levels were significantly elevated in preeclamptics vs. controls at time of enrollment. The sFlt1:PlGF ratio was correlated with CD31+/42− and CD 105+ EMPs (r=0.69 and r=0.51, respectively) in preeclampsia. Levels of CD31+/42− EMPs remained elevated 1-week postpartum (p=0.026). CONCLUSIONS-EMPs are elevated in preeclampsia. The correlation of EMPs and the sFlt1:PlGF ratio suggests that anti-angiogenesis is related to apoptosis of the endothelia. Endothelial damage persists one week after delivery.
Mechanisms of Enhanced Vascular Reactivity in Preeclampsia
Hypertension, 2011
Preeclamptic women have enhanced blood pressure response to angiotensin II and extensive systemic vascular infiltration of neutrophils. Neutrophils release reactive oxygen species that might activate the RhoA kinase pathway to enhance vascular reactivity. We hypothesized that enhanced vascular reactivity in preeclampsia is attributed to neutrophilmediated reactive oxygen species activation of the RhoA kinase pathway. Omental arteries were obtained at cesarean section and studied using a myograph system. We found that arteries of preeclamptic women had extensive infiltration of neutrophils and enhanced reactivity to angiotensin II. Treatment of arteries of normal pregnant women with reactive oxygen species or activated neutrophils enhanced vessel reactivity to angiotensin II mimicking preeclamptic vessels. Pretreatment with superoxide dismutase/catalase to quench reactive oxygen species or RhoA kinase inhibitor blocked enhanced responses in preeclamptic and normal vessels. Reactive oxygen species also enhanced vessel reactivity to norepinephrine, which was blocked by RhoA kinase inhibition. Treatment of arteries with reactive oxygen species increased RhoA kinase activity 3-fold, whereas culture of human vascular smooth muscle cells with angiotensin II and activated neutrophils or reactive oxygen species resulted in phosphorylation of key proteins in the RhoA kinase pathway. We conclude that enhanced vascular reactivity of omental arteries in preeclampsia is attributed to reactive oxygen species activation of the RhoA kinase pathway and that enhanced vascular reactivity is likely attributed to the infiltration of neutrophils. We speculate that neutrophil infiltration into systemic vasculature of preeclamptic women is an important mechanism for hypertension. (Hypertension.
Clinical and experimental hypertension (New York, N.Y. : 1993), 2017
To investigate the systemic and placental oxidant status as well as vascular function in experimental preeclampsia (PE) induced by nitro-L-arginine methyl ester (L-NAME). Fetal parameters and maternal blood pressure, proteinuria, mesenteric arterial bed (MAB) reactivity, and systemic and placental oxidative stress were compared between four groups: pregnant rats receiving L-NAME (60 mg/kg/day, orally) (P + L-NAME) or vehicle (P) from days 13 to 20 of pregnancy and nonpregnant rats receiving L-NAME (NP + L-NAME) or vehicle (NP) during 7 days. L-NAME administration during pregnancy induced some hallmarks of PE, such as hypertension and proteinuria. The P + L-NAME group presented lower weight gain and placental mass as well as reduced number and weight of live fetuses than P group. The vasodilator effect induced by acetylcholine (ACh) and angiotensin II (Ang II) was lower in the perfused MAB from NP + L-NAME and P + L-NAME than in control groups. Otherwise, the nitroglycerine-induced v...
The American journal of physiology, 1996
Uterine vasculature is less responsive than systemic vasculature to angiotensin II (ANG II)-induced vasoconstriction. We hypothesized that pregnancy augments basal and ANG II-stimulated endothelial prostacyclin (PGI2) and/or nitric oxide (NO) production, which locally increase vascular smooth muscle (VSM) adenosine 3',5'-cyclic monophosphate (cAMP) and guanosine 3',5'-cyclic monophosphate (cGMP), respectively. Uterine (UA) and systemic arteries (SA) from pregnant (P) and nonpregnant (NP) sheep were incubated with isobutylmethylxanthine. Basal PGI2, cAMP, and cGMP production was 2.4-, 1.6-, and 5.9-fold greater (P < 0.01) in UA from P vs. NP sheep; endothelium removal lowered (P < 0.05) values 69, 44, and 88%. Basal SA PGI2 and cAMP, but not cGMP, also were elevated by pregnancy. Indomethacin (Indo; 100 microM) decreased PGI2 and cAMP, but not cGMP production; N omega-nitro-L-arginine methyl ester (L-NAME; 10 microM) and methylene blue (MB, 10 microM) only decre...
Elevated plasma endothelial microparticles: Preeclampsia versus gestational hypertension
American Journal of Obstetrics and Gynecology, 2004
Objective: Elevated plasma endothelial microparticle levels have been found to be elevated in women with preeclampsia. However, their role in distinguishing preeclampsia from gestational hypertension remains to be elucidated. The objectives of this study were to compare endothelial microparticle levels among patients with preeclampsia, gestational hypertension, and healthy pregnant control subjects and to evaluate the effect of plasma from women with preeclampsia and gestational hypertension on the release of endothelial microparticles by renal microvascular endothelial cells.