ADAMTS13, FVIII, von Willebrand factor, ABO blood group assessment in preeclampsia

IntroductionPreeclampsia (PE) is a multifactorial disease characterized by high blood pressure and proteinuria after the 20th week of pregnancy. PE is associated with fibrin deposition in placental microcirculation and intrauterine fetal growth retardation. We evaluated FVIII activity, VWF and ADAMTS13 plasma levels, according to O and “non O” blood groups, in women with severe PE (sPE).MethodsThis case-control study included 140 women; 55 pregnant with sPE, 35 normotensive pregnant and 50 non-pregnant women. VWF and ADAMTS13 antigen levels were assessed by ELISA (American Diagnostica). FVIII activity was measured by automated coagulometric method (Dade Behring) and ABO blood groups phenotyping was performed by indirect technique.ResultsFVIII activity and VWF levels were significantly higher comparing either sPE to normotensive pregnant (P = 0.01; P = 0.05) and to non-pregnant women (P = 0.00 in both cases) or normotensive pregnant and non-pregnant women (P = 0.00 in both cases). A significant decrease in ADAMTS13 levels was observed comparing either sPE to normotensive pregnant (P = 0.02) and non-pregnant women (P = 0.00) or normotensive pregnant and non-pregnant women (P = 0.00). FVIII activity and VWF levels were associated to O and “non O” blood groups only in non-pregnant women.ConclusionsThe increase of FVIII activity and VWF levels and the decrease of ADAMTS13 in sPE are not associated to O and “non O” blood groups. These alterations in hemostatic markers in sPE largely surpass those physiologically determined by ABO blood groups influence and may have masked the effect of O and “non O” groups in this disease. A concomitant analysis of VWF levels and ADAMTS13 activity and antigenic levels will be important to clarify the imbalance between these parameters found in sPE in the present study.     

Lipid peroxide levels and lipid content of serum lipoprotein fractions of pregnant subjects with or without pre-eclampsia

Total serum lipids in normal pregnant subjects were significantly higher than those in non-pregnant subjects. This was due to an increase in the lipid content in all of the lipoprotein fractions, especially in VLDL. Serum lipids in pre-eclamptic subjects were higher than those in normal pregnant subjects. This was due to the increase in both VLDL and LDL.Serum lipid peroxide levels in pregnant subjects were significantly higher than those in non-pregnant subjects and further elevation of the levels was observed in pre-eclamptic subjects. The elevation of the peroxide levels in normal pregnant subjects was due to changes in all of the fractions of serum lipoproteins, especially in VLDL. The further elevation of peroxide in pre-eclamptic subjects resulted from an increase in HDL fraction.     

Serum from healthy pregnant women reduces oxidative stress in human umbilical vein endothelial cells

This study was conducted to compare the effects of serum from healthy pregnant women and that from pregnant women with pre-eclampsia on oxidative stress in endothelial cells in culture. Human umbilical vein endothelial cells (HUVECs) were incubated with serum from 18 pre-eclamptic, 18 healthy pregnant and 18 healthy non-pregnant women for 24 h. The levels of reduced glutathione (GSH) and lipid peroxides (LPOs) were measured in endothelial cell lysates. Measurement of malondialdehyde in combination with 4-hydroxyalkenals has been used as an indicator of LPOs. Serum from healthy pregnant women decreased significantly the LPO content in HUVECs in comparison with serum from pre-eclamptic women and healthy non-pregnant women (30.7+/-6.6 compared with 39.3+/-10.9 and 41.0+/-12.7 pmol/mg of protein respectively; P<0.003 and P<0.01 respectively). No differences in GSH content between the three groups (18.3+/-2.1 nmol/mg of protein for healthy pregnant, 19.2+/-3.3 nmol/mg for pre-eclamptic and 18.3+/-2.0 nmol/mg for healthy non-pregnant women) were found. Thus serum from normal pregnant women contains a factor(s) that decreases oxidative stress in human endothelial cells. This mechanism might be altered in pre-eclampsia.     

Intracellular and extracellular, ionized and total magnesium in pre-eclampsia and uncomplicated pregnancy.

Magnesium (Mg) and calcium (CA) concentrations in women with pre-eclampsia, women with an uncomplicated pregnancy and non-pregnant women were compared. Ionized serum magnesium and calcium concentrations and intracellular magnesium concentrations were measured in 15 pregnant women with severe pre-eclampsia, 34 uncomplicated pregnant women early, at midterm and preterm in their pregnancy and 24 non-pregnant women. The ionized calcium concentration did not chance during normal pregnancy or during pre-eclampsia relative to non-pregnant women. In contrast, elevated total and ionized magnesium serum concentrations were found in women with severe pre-eclampsia (total Mg = 0.85+/-0.11 mM, ionized Mg = 0.61+/-0.06 mM) relative to uncomplicated pregnant women (total Mg = 0.72+/-0.06 mM, ionized Mg = 0.53+/-0.03 mM). Total magnesium in pre-eclamptic women were similar to non-pregnant women. Intracellular ionized and total magnesium concentrations in mononuclear blood cells and erythrocytes were similar in pre-eclamptic women and women with uncomplicated pregnancy. Serum magnesium concentrations are elevated in severe pre-eclamptic women relative to women with uncomplicated pregnancy and are related to birth weight and gestational age at delivery. There may be a causal relationship since magnesium is involved in blood pressure regulation through an intracellular inhibition of NO synthase in endothelial cells.     

Failure to up-regulate VEGF165b in maternal plasma is a first trimester predictive marker for pre-eclampsia

Pre-eclampsia is a pregnancy-related condition characterized by hypertension, proteinuria and endothelial dysfunction. VEGF(165)b, formed by alternative splicing of VEGF (vascular endothelial growth factor) pre-mRNA, inhibits VEGF(165)-mediated vasodilation and angiogenesis, but has not been quantified in pregnancy. ELISAs were used to measure means+/-S.E.M. plasma VEGF(165)b, sEng (soluble endoglin) and sFlt-1 (soluble fms-like tyrosine kinase-1). At 12 weeks of gestation, the plasma VEGF(165)b concentration was significantly up-regulated in plasma from women who maintained normal blood pressure throughout their pregnancy (normotensive group, 4.90+/-1.6 ng/ml; P<0.01, as determined using a Mann-Whitney U test) compared with non-pregnant women (0.40+/-0.22 ng/ml). In contrast, in patients who later developed pre-eclampsia, VEGF(165)b levels were lower than in the normotensive group (0.467+/-0.209 ng/ml), but were no greater than non-pregnant women. At term, plasma VEGF(165)b concentrations were greater than normal in both pre-eclamptic (3.75+/-2.24 ng/ml) and normotensive (10.58 ng/ml+/-3.74 ng/ml; P>0.1 compared with pre-eclampsia) pregnancies. Patients with a lower than median plasma VEGF(165)b at 12 weeks had elevated sFlt-1 and sEng pre-delivery. Concentrations of sFlt-1 (1.20+/-0.07 and 1.27+/-0.18 ng/ml) and sEng (4.4+/-0.18 and 4.1+/-0.5 ng/ml) were similar at 12 weeks of gestation in the normotensive and pre-eclamptic groups respectively. Plasma VEGF(165)b levels were elevated in pregnancy, but this increase is delayed in women that subsequently develop pre-eclampsia. In conclusion, low VEGF(165)b may therefore be a clinically useful first trimester plasma marker for increased risk of pre-eclampsia.     

Stimulation of active renin release in normal and hypertensive pregnancy

1. Active plasma renin concentration but not total renin concentration is reduced in women with pregnancy-induced hypertension compared with normotensive pregnant women. This study was conducted to determine whether women with pregnancy-induced hypertension are able to stimulate release of active renin. 2. Active plasma renin concentration was measured as the generation of angiotensin I at physiological pH in the presence of excess renin substrate, and total renin concentration was determined in the same way after trypsin activation. Inactive plasma renin concentration was calculated as the difference between total renin and active plasma renin concentrations. 3. Resting active plasma renin concentration was significantly greater in third-trimester primigravidae compared with normotensive non-pregnant women and active plasma renin and total renin concentrations rose significantly without a fall in inactive plasma renin concentration in both groups after 2 h ambulation, suggesting increased release of active plasma renin and not conversion of circulating inactive to active renin. These responses were blunted in women taking oral contraceptives. 4. Although the active plasma renin concentration was significantly reduced in third-trimester primigravidae with pregnancy-induced hypertension, total renin concentration was not significantly different compared with normotensive women of similar gestation and in both groups 30 min 60 degrees head-up tilt increased active but not inactive plasma renin concentration. 5. These studies show that in normal pregnancy active plasma renin concentration can be stimulated to a similar extent as in non-pregnant women, despite a higher resting level. This appears to be due to increased secretion of active plasma renin rather than conversion of circulating inactive to active renin.(ABSTRACT TRUNCATED AT 250 WORDS)     

Normotension with decreased plasma renin activity and low serum ionic calcium levels: a prehypertensive state?

We studied the relationships between the renin-angiotensin-aldosterone system and calcium and magnesium levels in both serum and urine in 51 volunteer normotensive subjects, divided into two groups. Group 1 was made up of the 25 subjects whose levels of plasma renin activity were the lowest (1.93 +/- 0.70 ng/ml/hr). Group 2 comprised the 26 subjects with the highest plasma renin activity levels (4.80 +/- 0.84 ng/ml/hr). The following parameters were measured on all subjects: plasma renin activity and plasma and urinary aldosterone levels (by radioimmunoassay), serum ionic calcium levels (by Nova-2), total serum calcium, and serum and urinary magnesium values (by atomic absorption), serum and urinary sodium and potassium levels (by flame photometry), and creatinine clearance. In the group with low plasma renin activity (group 1), our findings included low serum ionic calcium levels (P less than .001); high coefficients of plasma aldosterone/plasma renin activity and urinary aldosterone/plasma renin activity (P less than .001); a significant correlation between the serum ionic calcium level and plasma renin activity (P less than .001); and an inverse correlation between systolic arterial tension and the serum ionic calcium level (P less than .05). These changes were more similar to change described in hypertensive patients with low plasma renin activity than to the findings in group 2 subjects. We speculate that normotensive subjects with low plasma renin activity present significant changes in the relationship between the renin-angiotensin-aldosterone system and sodium and calcium levels, and that this group is at risk for hypertension. A diet low in sodium and high in calcium could be an effective preventive measure.     

Altered Na+/H+ exchanger isoform 1 activity in immortalized lymphoblasts from women with pre-eclampsia: evidence for an intermediate phenotype

Previous studies have demonstrated a raised Na(+) content in leucocytes isolated from women with pre-eclampsia. Increased Na(+)/H(+) exchanger activity is one membrane transport abnormality that may contribute to this phenomenon and may be implicated in the abnormal volume homoeostasis and hypertension associated with the disease. Increased Na(+)/H(+) exchanger activity has been documented in nucleated white blood cells from both pre-eclamptic and post-partum pre-eclamptic women, and may suggest the importance of genetic influences on exchanger activity. In the present study, we used lymphoblasts from women with pre-eclampsia and from age- and gestation-matched normotensive pregnant controls to determine Na(+)/H(+) exchanger activity and intracellular resting pH using fluorimetry and the pH-sensitive dye BCECF-AM [bis(carboxyethyl)carboxyfluorescein acetoxymethyl ester]. Determination of Na(+)/H(+) exchanger protein abundance was performed by Western blotting. Intracellular pH was not significantly different in cells from pre-eclamptic women compared with those from normotensive controls. Na(+)/H(+) exchanger activity was measured when the intracellular pH was clamped at 6.0, and was found to be significantly higher in cells from pre-eclamptic women (20.77+/-0.92 mmol x min(-1) x l(-1)) compared with those from normotensive controls (15.22+/-0.92 mmol x min(-1) x l(-1); P =0.001). Na(+)/H(+) exchanger protein abundance was established to be similar in the two subject groups, suggesting that the turnover number for the Na(+)/H(+) exchanger is increased in the women with pre-eclampsia. These changes in Na(+)/H(+) exchanger activity indicate the importance of genetic factors in determining this particular phenotype, since in this cell culture model of pre-eclampsia it is likely that environmental or hormonal influences present in vivo would have declined. Overactivity of the Na(+)/H(+) exchanger may contribute to the raised intracellular Na(+) concentration reported previously in white blood cells from women with pre-eclampsia.     

Platelet intracellular free calcium concentration in normotensive and hypertensive pregnancies in the human

1. Basal and stimulated platelet intracellular free calcium concentrations were measured in non-pregnant women and in third trimester patients who were either normotensive or who had pregnancy-induced hypertension or pre-eclampsia. There were 15 subjects in each group. 2. A trend for a reduction of the maximal response of platelet calcium levels to stimulation by 5-hydroxytryptamine was seen in pregnant groups compared with nonpregnant subjects, but this was significant only in pre-eclampsia. 3. No significant differences in basal or adenosine 5'-pyrophosphate-stimulated levels of platelet intracellular free calcium concentration were observed between the four groups. 4. These results illustrate that basal platelet calcium levels are unchanged in hypertension of pregnancy. Alterations in basal platelet calcium levels may not be involved in the platelet activation that is a feature of pre-eclampsia.     

Relationships between blood pressure, age, plasma renin activity and electrolyte excretion in normotensive subjects

Plasma renin activity (PRA), supine and sitting blood pressure (BP) and urinary sodium and potassium excretion were studied in 120 normotensive subjects aged 22--78 years, during strictly standardized conditions. PRA was measured after 1 h supine rest (basal PRA) after ambulation for 3--4 h (upright PRA) and after stimulation with 80 mg frusemide orally (stimulated PRA). PRA was determined with a new, simple, accurate and sensitive radioimmunoassay method. Supine and sitting systolic BP increased with age but no such correlation was found for the diastolic BP. No correlation could be shown between the BP levels and either the sodium or the potassium excretions. PRA levels increased about two-fold from basal to upright levels and about four-fold from basal levels after stimulation. No differences in mean PRA-levels were seen between males and females. We could not demonstrate any correlations between PRA-levels and 24 h sodium or potassium excretions, nor was there any relationship between age and PRA. Reference ranges are given for basal, upright and stimulated PRA in normotensive subjects. From these reference values a rational and clinically useful subdivision into low, normal and high renin groups can be made for hypertensive patients.     

Increased adenosine deaminase in hydatidiform mole.

BACKGROUND: The aim of the current study was to investigate levels of adenosine deaminase in plasma of patients with hydatidiform mole. METHODS: Plasma adenosine deaminase levels were determined in 17 women with normal pregnant course, in 17 women with hydatidiform mole, and in 17 non-pregnant healthy volunteers. RESULTS: Mean adenosine deaminase activity in the hydatidiform mole group was 121.5+/-24.8 U/L, significantly higher than in the pregnant control (7.8+/-6.5 U/L; p<0.0001) and non-pregnant control groups (6.4+/-7.4 U/L; p<0.0001). A cutoff level of 40.5 U/L was found, with both sensitivity and specificity of 100%. CONCLUSIONS: Adenosine deaminase may play a role in the development of hydatidiform mole.     

先兆子痫患者血清视黄醇结合蛋白4的表达水平

目的 检测先兆子痫患者血清视黄醇结合蛋白4（RBP4）和超敏C反应蛋白（hsCRP）的水平,探讨RBP4与先兆子痫发病的关系.方法 采取先兆子痫组61例（轻度先兆子痫组31例、重度先兆子痫组30例）,正常妊娠组30例,非孕对照组30例,采用酶联免疫吸附试验等法测定其血清中RBP4和hsCRP浓度,同时测定胰岛素抵抗指数和血脂.结果 轻度和重度先兆子痫组血清RBP4均明显高于正常妊娠组和非孕对照组,差异均有统计学意义（q分别=2.24、2.46、2.61、2.83,P均＜0.05）,hsCRP水平明显高于正常妊娠组和非孕对照组,差异均有统计学意义（q分别=2.15、2.21、2.43、2.55,P均＜0.05）;重度先兆子痫组RBP4和hsCRP均明显高于轻度先兆子痫组,差异均有统计学意义（q分别=3.25、3.17,P均＜0.05）;先兆子痫孕妇血清RBP4水平与血清hsCRP和HOMA-IR呈正相关（r分别=0.42,0.38,P均＜0.05）.结论 先兆子痫患者血清RBP4水平升高,可作为临床观察指标.     

Capillary permeability and extracellular fluid volumes in pregnancy-induced hypertension

1. Capillary permeability was determined by the disappearance rate of Evans Blue dye from plasma in healthy non-pregnant women, normal third-trimester primigravidae and primigravidae with pregnancy-induced hypertension. 2. Extracellular fluid volume was determined from the disappearance curves of injected mannitol in the same subjects and the plasma volume was measured by the Evans Blue dye dilution technique. 3. In normal pregnancy capillary permeability was not altered from that of non-pregnant subjects. Although extracellular fluid volume and plasma volume were increased in normal pregnant compared with non-pregnant women, the distribution of fluid between plasma volume and interstitial fluid volume was unaltered. 4. Women with established pregnancy-induced hypertension had a more rapid Evans Blue disappearance rate and a lower plasma volume than normal pregnant women, independent of the presence of proteinuria. Maternal plasma volume correlated positively and significantly with fetal birth weight in women with pregnancy-induced hypertension, emphasizing the important relationship between maternal plasma volume and fetal outcome. 5. The increased capillary permeability in women with pregnancy-induced hypertension was associated with a reduction in the plasma volume/interstitial fluid volume ratio but a normal extracellular fluid volume, suggesting that the reduced plasma volume did not result from sodium loss but rather from a redistribution of the total extracellular fluid volume. These changes did not differ significantly in subgroups with and without oedema.     

血浆D-二聚体在临产孕妇分娩前后及分娩方式中的应用研究

目的 评价孕妇分娩前后以及分娩方式体内血浆D-二聚体水平变化的临床意义.方法 收集184例临产孕妇和非孕健康对照组40例,将临产孕妇分成自然分娩组(n=83),剖宫产组(n=101);采用酶免荧光法和凝固法检测孕妇血浆D-二聚体和纤维蛋白原水平,评价D-二聚体与纤维蛋白原的相关性,并随访其妊娠结局,行弥散性血管内凝血(DIC)追踪.结果 剖宫产组年龄、孕龄、住院天数明显大于自然分娩组;所有孕妇体内D-二聚体和纤维蛋白原水平明显高于健康对照组(P<0.01),孕妇产后D-二聚体水平高于分娩前,而且剖宫产组产后第1天D-二聚体水平也显著高于自然分娩组产后第1天(P<0.01);临产孕妇中共有5例发生产后DIC,D-二聚体与纤维蛋白原无相关性(P>0.05).结论 妊娠妇女机体处于高凝状态,体内血浆D-二聚体和纤维蛋白原水平明显高于非孕健康人群,然而对于高危人群应该动态监测D-二聚体水平,降低血栓事件的发生.     

蛋白Z和蛋白Z依赖的蛋白酶抑制物在正常妊娠妇女中的变化和意义

目的探讨不同孕期正常妊娠妇女血浆蛋白Z(PZ)、蛋白Z依赖的蛋白酶抑制物(ZPI)浓度及其临床意义。方法选择正常未孕妇女、妊娠早期(14～27周)、妊娠晚期(28～40周)各50例,用酶联免疫吸附试验(ELISA)竞争法测定其血浆PZ和ZPI浓度,用凝固法检测凝血酶原时间(PT)、活化部分凝血活酶时间(APTT)、凝血酶时间(TT)和纤维蛋白原(Fg)浓度。结果 PZ和ZPI从正常未孕妇女至妊娠早期、妊娠晚期,其血浆浓度逐渐下降,妊娠后期比正常未孕妇女PZ下降16.1%,ZPI下降22.8%。妊娠早期、妊娠后期与正常未孕妇女比较,PT、TT明显缩短(P<0.01),Fg明显增高(P<0.01);妊娠晚期与妊娠早期比较PT和TT明显缩短(P<0.05),Fg明显增高(P<0.05);妊娠后期组APTT与正常未孕妇女比较明显缩短(P<0.05)。PZ、ZPI浓度降低与PT异常有一定相关性。结论随着妊娠周数增加,孕妇凝血因子活性和凝血功能增强,可能与抗凝物质PZ、ZPI血浆浓度逐渐下降有关,这种妊娠期生理变化为产后快速有效止血提供了物质基础,但也可能使妊娠期血栓形成的风险增大。     

Abnormal vascular function and morphology in pre-eclampsia: a study of isolated resistance vessels

In order to obtain direct information about vascular changes associated with pre-eclampsia, the morphological and functional characteristics of isolated omental resistance vessels from 11 women with pre-eclampsia, 10 normotensive pregnant women and eight normotensive non-pregnant women were determined. In vessels from the women with pre-eclampsia, the ratio of media thickness to lumen diameter was increased, compared with that in vessels from the other two groups. The vessels from the women with pre-eclampsia had an increased responsiveness to angiotensin II and a decreased rate of relaxation, but only when compared with the vessels from the normotensive pregnant women. However, no difference in responsiveness to noradrenaline was found between any of the groups. The angiotensin II responsiveness of the vessels from the women with pre-eclampsia and from the non-pregnant women were similar, suggesting that pre-eclampsia is associated with an absence of the change in vascular function which normally occurs during pregnancy. The study provides direct evidence for an involvement of vascular abnormalities in the pathogenesis of pre-eclampsia.     

血浆肾素、血管紧张素Ⅱ、醛固酮水平与先兆子痫的关系研究

目的 探讨血浆肾素(PRA)、血管紧张素Ⅱ(AngⅡ)以及醛固酮(Ald)的水平与妊娠期先兆子痫的关系.方法 选择妊娠期先兆子痫患者27例作为病例组,随机选取同期健康妊娠妇女51例、健康未妊娠妇女35例作为对照组,检测其血浆PRA、AngⅡ及Ald水平,并对各指标进行组间比较.结果 与健康妊娠妇女相比,先兆子痫患者的AngⅡ水平明显升高,而PRA、Ald水平明显下降,差异均有统计学意义(P<0.05);与健康未妊娠妇女相比,先兆子痫患者的AngⅡ水平也明显升高(P<0.05).结论 先兆子痫患者的血浆PRA、AngⅡ、Ald水平发生变化,可能与它们参与先兆子痫的病理生理过程有关.     

Abnormal cation composition and transport in erythrocytes from hypertensive patients

Red cell sodium and potassium were determined in 100 untreated subjects with uncomplicated essential hypertension and compared with the values from 908 healthy normotensive control subjects. Red cell sodium concentration (expressed as mmol/l of erythrocytes) was significantly higher in hypertensive than in normotensive subjects. Red cell potassium concentration (in mmol/l of erythrocytes) was not significantly different in the two groups. Passive efflux of red cell potassium into buffered isotonic sucrose solution determined in eight hypertensive and nine normotensive subjects showed a lower potassium efflux rate in the hypertensive subjects. Comparison of active sodium efflux in sixteen hypertensive and fourteen normotensive subjects showed that ouabain-sensitive active sodium efflux was higher in red cells of normotensive than in those of hypertensive subjects.     

Comparative assessment of matrix metalloproteinase (MMP)-2 and MMP-9, and their inhibitors, tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2 in preeclampsia and gestational hypertension

ObjectivesTo compare the circulating levels of matrix metalloproteinase (MMP)-2, MMP-9, tissue inhibitors of metalloproteinase (TIMP)-1, TIMP-2, and the MMP-9/TIMP-1 and MMP-2/TIMP-2 ratios in preeclampsia and gestational hypertension with those found in normotensive pregnancies.Design and methodsWe studied 83 pregnant women (30 healthy pregnant women with uncomplicated pregnancies, 26 with gestational hypertension, and 27 with preeclampsia) and 30 healthy nonpregnant women in a cross-sectional study. MMP and TIMP concentrations were measured in plasma samples by gelatin zymography and ELISA, respectively.ResultsWe found higher plasma pro-MMP-9 levels, and higher pro-MMP-9/TIMP-1 ratios in women with gestational hypertension (95%-CI: 1.031 to 2.357, and 0.012 to 0.031, respectively), but not with preeclampsia, compared with those found in normotensive pregnant women (95%-CI: 0.810 to 1.350, and 0.006 to 0.013, respectively; both P < 0.05). We found no significant differences in pro-MMP-2 levels (P > 0.05).ConclusionsThe higher net MMP-9 (but not MMP-2) activity in gestational hypertension compared with normotensive pregnancy suggests that MMP-9 plays a role in the pathophysiology of gestational hypertension. Conversely, the lack of such alterations in preeclampsia is consistent with the notion that different pathophysiological mechanisms are involved in these hypertensive disorders.     

The role of the vascular endothelium in the contractile responses of human chorionic plate artery in pre-eclampsia to prostaglandin F2alpha, 5-hydroxytryptamine,and potassium chloride

This study characterises the reactivity of chorionic plate artery in preeclampsia to prostaglandin F_2alpha (PGF_2alpha), 5-hydroxytryptamine (5-HT), and potassium chloride (KCl) and examines the role of the vascular endothelium in these responses. Ring segments of the chorionic plate arteries of women after normal and pre-eclamptic pregnancies were contracted by PGF_2alpha, 5-HT, and KCl. The experiments were carried out in the presence and absence of endothelium, and on intact rings treated with 10⁻⁶M indomethacin. The maximal contractile responses of rings from pre-eclamptic women to 5-HT, PGF_2alpha, or KCl were significantly greater than those of rings from normotensive pregnant women. The EC₅₀ values of responses were significantly lower in rings from pre-eclamptic subjects. Endothelium removal and treatment of the rings with indomethacin had no effect on the contractile responses of rings from normotensive pregnant women to all the agents, but significantly increased the EC₅₀ value and decreased the maximal contractile responses of rings from pre-eclamptic women to 5-HT and PGF_2alpha. While de-endothelialisation increased the EC₅₀ value for responses of the rings from pre-eclamptic women to KCl, pretreatment with indomethacin did not significantly affect the KCl-induced responses. The results of the study suggest that pre-eclampsia enhanced the reactivity of human chorionic plate artery to 5-HT, PGF_2alpha, and KCl through the involvement of endothelial derived contracting factors. The increased responses to 5-HT and PGF_2alpha were inhibited by indomethacin, but those to KCl were not.