Severe hyponatremia associated with pre-eclampsia

Abstract

Background: Pre-eclampsia associated hyponatraemia is a very rare condition that can potentially lead to serious maternal and fetal complications and that constitute a diagnostic and therapeutic challenge even for an experienced physician.

Case report: A 25-year old female presented to the clinic at 25.3 weeks of gestation with mild physical signs of edema along with hypertension, proteinuria, and a severe hyponatremia (113?mEq/L). Hyponatremia was classified as hypervolemic and resolved 72 hours after the delivery with water restriction.

Conclusions: The pathogenesis of pre-eclampsia associated hyponatremia is relatively unknown. A non-osmotic stimulation of vasopresin release in the setting of a hypervolemic state with low effective circulating plasma volume is thought to be the main mechanism. Advanced maternal age and nephrotic range proteinuria have been postulated as risk factors, but their causal role remains unclear. Fluid restriction is a reasonable treatment, and maternal outcomes are favourable. This condition is a rare indication for urgent delivery, but neonatal outcomes are variable.     

Evaluation of inflammatory mediators in the deciduas of pregnant women with pre-eclampsia/eclampsia

Objective: The objective was to evaluate some inflammatory mediators, i.e. cytokines that induce and inhibit nitric oxide (NO) synthase, in pregnant women with pre-eclampsia/eclampsia (PE/E) compared to clinically normal patients.

Methods: Placental fragments were collected from 46 pregnant patients, including 30 clinically normal subjects and 16 women with PE/E, and stored in NP40-containing phosphate buffer in a freezer at ?70?°C until the time of solubilization. Cytokines IL-4, IL-10, IL-13, TNF-α and IFN-γ were assayed by ELISA and NO was estimated by the Griess reaction after reduction.

Results: Patients with PE/E presented significantly lower placental levels of IL-10 and IL-3 than the control group (p?<?0.05). On the other hand, IL-4, TNF-α and IFN-γ levels were similar on the two groups, whereas nitrite/nitrate levels were significantly lower in the PE/E group. A higher inflammatory balance was observed in patients with PE/E compared to normal subjects (p?<?0.05).

Conclusion: Patients with PE/E present lower levels of Th2 cytokines associated with a pro-inflammatory balance as evaluated by the IL-10/TNF-α ratio, as well as lower nitrite/nitrate levels, than controls.     

Maternal and fetal plasma zinc in pre-eclampsia.

Zinc is important for fetal growth and is involved in several important enzyme systems. Maternal and umbilical plasma zinc concentrations were determined in 52 parturient women with mild and severe pre-eclampsia, and were compared with those obtained from 20 women in labor whose pregnancies had progressed normally. A decrease in maternal as well as umbilical plasma zinc concentrations was observed in pre-eclamptic women, and this decrease was statistically significant in severe pre-eclampsia. The causes of these changes in plasma zinc concentrations in pre-eclampsia were discussed, and the possible adverse effects of zinc deficiency on the mother and fetus were mentioned. Low plasma zinc concentrations in pre-eclampsia may be a sign of zinc deficiency, implying possible risks to the mother and her fetus. It is recommended that maintenance of adequate dietary zinc nutrition during pregnancy, and particularly in pre-eclampsia, is important.     

Maternal cardiac function and uterine artery Doppler at 11-14 weeks in the prediction of pre-eclampsia in nulliparous women

Objective  To assess maternal cardiac function in nulliparous women in the first trimester of pregnancy and evaluate its potential role for predicting pre-eclampsia and small for gestational age (SGA).
Design  Prospective, observational, cross-sectional study.
Setting  Maternity unit of a teaching hospital.
Population  Nulliparous women with singleton pregnancies presenting consecutively for routine antenatal care ( n = 534).
Methods  Two-dimensional and M-mode echocardiography and uterine artery Dopplers were carried out at 11-14 weeks.
Main outcome measures  Cardiac output (CO), stroke volume (SV), mean arterial pressure (MAP), total vascular resistance and uterine artery pulsatility index (UAPI) were compared in four outcome groups according to the development of pre-eclampsia and/or SGA.
Results  Compared with the normal outcome group ( n = 457), in those with pre-eclampsia but not SGA ( n = 8), CO and MAP were increased; in the group with pre-eclampsia and SGA ( n = 19) MAP, TRP and UAPI were increased and in the group with SGA but no pre-eclampsia ( n = 50) total peripheral resistance and UAPI were increased. Independent predictors of pre-eclampsia were MAP, SV and UAPI and of SGA SV and UAPI.
Conclusions  Alterations in maternal cardiac function and UAPI are observed in the first trimester of pregnancy in nulliparous women that subsequently develop pre-eclampsia and/or SGA.     

Serum humanin concentrations in women with pre-eclampsia compared to women with uncomplicated pregnancies

Purpose: To compare serum humanin concentrations in pregnant women with and without pre-eclampsia (PE).

Materials and methods: A case-control study where pregnant women (PE group, n?=?37; control group, n?=?34) studied through history parameters (gynecological, obstetrical, personal, and family), physical and sonographic examination parameters [body mass index (BMI), blood pressure obstetrical ultrasound], and biochemical/hormonal assays [creatinine, urea, serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), uric acid, platelets, urinary protein, and humanin].

Results: There was no difference in basic characteristics between women with PE and control, except in parity and gravidity. Humanin concentrations were higher in women with PE compared to controls (422.2?±?33.5 vs. 319.1?±?28.1?pg/ml, p?=?0.023). In a binary logistic analysis, humanin was associated with the presence of PE [odds ratio 1.003, 95% confidence interval (CI); 1.000–1.006]. The ability of humanin to discriminate between women with PE and controls was evaluated by receiver operation characteristics (ROC) analysis [area under the curve (AUC) 0.639, 95% CI; 0.510–0.768, p?=?0.045].

Conclusions: Serum humanin concentrations are increased in women with PE, compared to women with uncomplicated pregnancies, suggesting a potential protective role of humanin against the oxidative stress and endothelial dysfunction occurring in PE.     

Association between maternal serum 25-hydroxyvitamin D level and pre-eclampsia

Objectives: The objective of the study was to evaluate the association of maternal plasma levels of 25-hydroxyvitamin D (25(OH)D) at late second and third trimester and the risk of pre-eclampsia.

Methods: In this prospective cohort study, maternal plasma 25(OH)D levels were measured at late second and third trimester in 77 women who later developed pre-eclampsia (31 non-severe and 46 severe cases) and 180 women without pre-eclampsia.

Results: The mean gestational age of the timing of the blood sampling was 31.1?±?4.4 at control group, 32.6?±?5.7 at non-severe pre-eclamptic group and 32.3?±?5.4 at severe pre-eclamptic group. The mean 25(OH)D concentration was significantly low in severe pre-eclampsia group (5.8?±?4.5?ng/ml) than non-severe pre-eclampsia (11.8?±?7.3?ng/ml, p?=?0.039) and control groups (14.9?±?12.0?ng/ml, p?<?0.0001). There was no statistically significant difference in 25(OH)D concentration between non-severe pre-eclamptic and control groups (p?=?0.404). In women with 25(OH)D concentration <20?ng/ml, a 12.45-fold increase in the odds of severe pre-eclampsia were detected.

Conclusion: Women with severe pre-eclampsia had low serum 25(OH)D levels. The correlation between maternal 25(OH)D levels and aspartate aminotransferase, alanine transaminase, serum creatinine levels, platelet count were not determined. 25(OH)D levels may be used as an independent predictive marker of severe pre-eclampsia.     

子痫前期-子痫患者胎盘组织中内皮型一氧化氮合酶运输介导物与内皮型一氧化氮合酶的相关性研究

目的:通过测定子痫前期-子痫患者胎盘组织中内皮型一氧化氮合酶运输介导物(endothelial nitric oxide synthase traffic inducer,NOSTR IN)和内皮型一氧化氮合酶(endothelial nitric oxide synthase,eNOS)的表达,探讨它在子痫前期-子痫发病中的作用。方法:采用逆转录-聚合酶链反应(RT-PCR)检测21例子痫前期-子痫患者(病例组)和17例正常晚孕妇女(正常组)胎盘组织中NOSTR IN mRNA的表达;W estern blot检测胎盘组织中NOSTR IN和eNOS蛋白质的表达;分光光度法测定胎盘组织中eNOS的活性;应用硝酸还原酶法测定孕妇静脉血中的NO代谢产物亚硝酸基/亚硝基(NO2-/NO3-)。结果:病例组患者胎盘组织中NOSTR IN mRNA呈强表达,明显高于正常组(P<0.01);W esternblot显示两组胎盘组织中均有58kDa的NOSTR IN蛋白质表达,但病例组表达量明显增高(P<0.01),同时也均有145kDa的eNOS蛋白质表达,两组表达量比较无差异(P>0.05);病例组患者胎盘组织eNOS活性为13.727±3.58 U/mg,与正常组的21.69±3.84U/mg比较降低显著(P<0.01);病例组孕妇外周血清NO2-/NO3-为38.56±8.49μmol/l,与正常组的65.37±9.61μmol/l比较显著降低(P<0.01);病例组胎盘组织中NOSTRN表达水平与eNOS活性呈负相关(r=-0.57,P<0.01)。结论:子痫前期-子痫患者胎盘组织中NOSTR IN表达水平升高,eNOS活性降低,这可能在子痫前期-子痫的发病中起重要作用。     

Lipoprotein(a) levels in women with pre-eclampsia and in normotensive pregnant women

AIM: To determine if plasma lipoprotein(a) levels are elevated in pre-eclampsia and if so, their association with the severity of the disease. METHODS: Ninety-one pre-eclamptic (48 mild, 43 severe) and 40 healthy normotensive pregnant women at more than 32 gestational weeks were recruited into study. Plasma levels of lipoprotein(a), lipids, total protein, albumin and fibrinogen were measured in all subjects. RESULTS: All groups were comparable with respect to maternal age, maternal weight, gravidity and parity. Platelet count, total serum protein and albumin levels were significantly decreased, whereas fibrinogen levels significantly increased in the pre-eclamptic group. There was no difference between the groups with respect to total cholesterol and low-density lipoprotein levels. In the pre-eclampsic group, triglyceride and very-low-density lipoprotein concentrations were significantly higher, whereas high-density lipoprotein levels were significantly lower. No difference in serum lipoprotein(a) levels was found between the three groups. CONCLUSIONS: No statistically significant difference existed between normotensive pregnant, and pre-eclamptic women, with regard to plasma lipoprotein(a) levels. It is improbable that high serum lipoprotein(a) levels are risk factors for the development of pre-eclampsia; however, elevated triglyceride-rich lipoproteins might cause endothelial damage leading to pre-eclampsia.     

Expression of endothelial nitric oxide synthase traffic inducer in the placentas of women with pre-eclampsia.

OBJECTIVE: To investigate the expression of endothelial nitric oxide synthase traffic inducer (NOSTRIN) in the placenta of women with pre-eclampsia (PE) and discuss its role in the pathogenesis of PE. METHODS: Western blot analysis was used to detect the expression of NOSTRIN and endothelial nitric oxide synthase (eNOS). The activity of eNOS in placental tissue was assayed by spectrophotometry. Serum and placental NO(2)/NO(3), the stable metabolic end product of NO, was measured using nitrate reductase. RESULTS: Western blot analysis showed that the protein level of NOSTRIN was significantly higher in women with PE than in the control group (P<0.01). However, no significant difference between groups was observed in the expression of placental eNOS (P>0.05). The activity of eNOS was significantly decreased in women with PE (13.727+/-3.58 U/mg) compared with the control group (21.69+/-3.84 U/mg) (P<0.01). The placental levels of NO(2)/NO(3) were significantly lower in women with PE (27.53+/-8.51 micromol/mg) than in the control group (44.38+/-9.59 micromol/mg) (P<0.01). The levels of serum NO(2)/NO(3) were significantly lower in women with PE (48.56+/-8.49 micromol/L) than in the control group (65.37+/-9.61 micromol/L) (P<0.01). A significant negative correlation existed between the expression of NOSTRIN protein and the activity of eNOS in the placental tissues of women with PE (r=-0.57, P<0.01). CONCLUSION: The level of NOSTRIN expression in the placental tissues of women with PE is increased and is negatively correlated with the activity of eNOS-which may play an important role in the pathogenesis of PE.     

Severe pre-eclampsia is associated with abnormal trace elements concentrations in maternal and fetal blood

Objective: The study was aimed to compare trace elements concentrations in women with and without severe pre-eclampsia (PE). Methods: A prospective case-control study was conducted comparing 43 parturients with severe PE (who received magnesium sulfate [MgSO4]) and 80 healthy parturients and their newborns, matched for gestational age and mode of delivery. Inductively coupled plasma mass spectrometry (ICPMS) was used for the determination of zinc (Zn), copper (Cu), selenium (Se) and magnesium (Mg) levels in maternal as well as arterial and venous umbilical cord serum. Results: Zn levels (µg/L) were significantly higher in fetal arterial and venous blood of the PE group (947.3?±?42.5 vs. 543.1?±?226, 911.1?±?220.2 vs. 422.4?±?145, p?<?0.001; respectively). Se levels (µg/L) were significantly lower in maternal and fetal arterial and venous cord blood of the PE group (98.6?±?24.2, 110.7?±?19.4, 82?±?17.8 vs. 111.6?±?17.6, 82.1?±?17.4 vs. 107.1?±?25.7, p?<?0.001; respectively). Cu levels (µg/L) were significantly lower in fetal arterial and venous cord blood (581.6?±?367.4 vs. 949?±?788.8, p?=?0.022, 608.3?±?418.1 vs. 866.9?±?812.6, p?=?0.001 respectively) but higher in maternal blood (2264.6?±?751.7 vs. 1048?±?851.1, p?<?0.001). These differences remained significant while controlling for the mode of delivery. Mg levels were significantly higher in the PE group as compared with the control group. Conclusions: Severe PE is associated with abnormal concentrations of Zn, Cu and Se. Therefore, trace elements may have a crucial role in the pathogenesis of severe PE.     

Nitric oxide and peroxynitrite platelet levels in women with small-for-gestational-age fetuses

Objective  The placenta produces reactive oxygen species (ROS) including nitric oxide (NO) and peroxynitrite (ONOO⁻) that have pronounced effects on placental function. Excessive ROS production may occur in pathological pregnancies, such as those complicated by small-for-gestational-age (SGA) fetuses.
Design  The aim of the present work was to study NO and ONOO⁻ levels in platelets of pregnant women with SGA fetuses compared with a control group.
Setting and population  The study was performed on 30 pregnant women with SGA fetuses (SGA group) and on 30 healthy pregnant women (appropriate-for-gestational-age [AGA] group) matched for maternal and gestational age. All women included in this study were in the third trimester of pregnancy.
Methods  Platelets were isolated by differential centrifugation. NO metabolites, after enzymatic conversion followed by the Griess reaction, were measured as nitrite by spectrophotometric detection. Peroxynitrite (ONOO⁻) levels were evaluated using the fluorescence probe 2,7-dichlorofluorescein diacetate (DCFDA).
Main outcome measures  The following determinations were made: platelet nitric oxide and peroxynitrite levels in the SGA group and controls; inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS) and nitrotyrosine (N-Tyr) expression in the same groups.
Results  Our results show that both platelet NO and ONOO⁻ levels were significantly higher in the SGA group than in the controls.
Conclusion  Increased platelets levels of nitric oxide and peroxynitrite might play a role in the pathophysiology of intrauterine growth restriction. Further investigations are in progress to clarify if these molecules are pathogenetic factors, an epiphenomenon or a pathophysiological marker.     

Ibuprofen versus acetaminophen as a post-partum analgesic for women with severe pre-eclampsia: randomized clinical study

Objective: To compare differences in blood pressure levels between patients with severe post-partum pre-eclampsia using ibuprofen or acetaminophen.

Methods: A randomized controlled trial was made in women with severe pre-eclampsia or superimposed pre-eclampsia after vaginal birth. The patient was randomly selected to receive either 400?mg of ibuprofen every 8?h or 1?g of acetaminophen every 6?h during the post-partum. The primary variable was systolic hypertension ≥150?mmHg and/or diastolic hypertension ≥100?mmHg after the first 24?h post-partum. Secondary variables were the arterial blood pressure readings at 24, 48, 72, and 96?h post-partum and maternal complications.

Results: A total of 113 patients were studied: 56 in the acetaminophen group and 57 in the ibuprofen group. With regard to the primary outcome, more cases were significantly hypertensive in the ibuprofen group (36/57; 63.1%) than in the acetaminophen group (16/56; 28.6%). Severe hypertension (≥160/110?mmHg) was not significantly different between the groups, 14.5% (acetaminophen) and 24.5% (ibuprofen). The levels of arterial blood pressure show a hammock-shaped curve independent of the drug used, however, is more noticeable with ibuprofen.

Conclusions: This study shows that ibuprofen significantly elevates blood pressure in women with severe pre-eclampsia during the post-partum period.     

Pregnancy outcome in women presenting with pre-eclampsia at less than 25 weeks gestation

OBJECTIVE: We aimed to (i) assess maternal and perinatal outcomes in pre-eclampsia at < 25(0) weeks; and (ii) determine if any antenatal factors were associated with adverse maternal and perinatal outcomes. DESIGN: A retrospective study. SETTING: Tertiary referral hospital, Auckland, New Zealand. METHODS: Data were extracted from the clinical record and hospital database. The study population involved women admitted with pre-eclampsia at < 25(0) weeks, with a live singleton pregnancy, from 1997 to 2004 and managed expectantly. OUTCOME MEASURES: Maternal morbidity, perinatal death, neurodevelopmental outcome at 18 months, small for gestational age assessed by population and customised birthweight centiles. RESULTS: Gestation at admission was the only antenatal variable associated with adverse perinatal outcome. Of 14 women admitted < 23 weeks, no babies survived, but eight (62%) babies of women admitted in the 24th week (24(0)-24(6)) survived. Neurodevelopmental outcome was assessed in eight of nine survivors; two (25%) had moderate and two (25%) had minor disability. All babies in this cohort had birthweights < 5th customised centile. Only one baby (10%) weighing < 500 g survived. CONCLUSION: Maternal morbidity was high in this expectantly managed cohort. As no babies survived when pre-eclampsia occurred before 23 weeks, induction of labour should be considered. In the 24th week two-thirds of babies survived and 25% had moderate handicap. This information may help clinicians and women in the future to make informed choices about management.     

Plasma anti-oxidant status and lipid profile in non-gravida women with a history of pre-eclampsia

Objective:  To investigate the total plasma anti-oxidant status, the plasma lipid profile and the uterine artery Doppler velocity waveform in formerly pre-eclamptic women.
Methods:  Thirty-two formerly pre-eclamptic, non-gravida women constituted the study group, while 28 age-matched non-gravida women who had never had pre-eclampsia served as control subjects. On days 17–19 of their menstrual cycle, fasting plasma samples were collected for total anti-oxidant status (TAS) and lipid profile evaluation, and uterine artery Doppler velocity waveform studies were performed. Results were analyzed with Mann–Whitney U -test and Pearson correlation analysis.
Results:  There was no significant difference between the groups in means of the uterine artery Doppler velocity waveforms and the plasma lipid levels, but body mass index values were significant ( P  < 0.005). The TAS value was subnormal in 72% of the formerly pre-eclamptic group and in 35% of the control group. The mean plasma TAS value was 1.20 ± 0.05 mmol/L and was significantly lower in the study group when compared with the control group ( P  < 0.05).
Conclusion:  The current study reveals significantly decreased TAS in women with a history of pre-eclampsia, which may have an important role in pathophysiology.     

Soluble Flt-1 as a diagnostic marker of pre-eclampsia

BACKGROUND: Serum levels of soluble fms-like tyrosine kinase (sFlt-1) increase in pre-eclampsia (PE). Aims: To determine whether concentrations of serum sFlt-1 can differentiate PE or superimposed PE (SPE) from gestational hypertension (GH) or chronic hypertension (CH). METHODS: Blood was collected from pregnant women being investigated for hypertension (blood pressure of > 140 and/or 90 mmHg). Normotensive (NP) and pre-eclamptic (PE-C) control ranges were measured. RESULTS: Patients with evolving hypertension in pregnancy eventually fell into four groups: GH (n = 14), PE (n = 7), CH (n = 9) and SPE (n = 9). Patients who later developed pre-eclampsia had a higher sFlt-1 (PE: 2.61 ng/mL and SPE: 2.77 ng/mL, respectively) than GH (P < 0.001) or CH (1.05 ng/mL, P = 0.11). Women with established PE at recruitment (PE-C; (n = 18) (3.13 ng/mL; interquartile range (IQR): 2.14-4.17 ng/mL) had a median sFlt-1 higher than NP (n = 18) (0.47 ng/mL; IQR: 0.11-0.89) (P < 0.0008). Patients with GH compared to NP had a slight increase (1.33 ng/mL, P < 0.003). Using a sFlt-1 cut-off of > or = 1.9 ng/mL yielded a sensitivity of 94% (95% confidence interval (CI) 73-100%) and specificity of 78% (95% CI 64-82%). CONCLUSIONS: sFlt-1 was elevated in women with PE compared to NP. The sFlt-1 also differentiated women destined to develop PE among those who presented with a diagnostic rise in maternal blood pressure. The sFlt-1 test is a useful diagnostic test for PE.     

Cystatin C as an indicator of renal damage in pre-eclampsia

ABSTRACT

Objective

To assess the predictive abilities of serum and urinary cystatin C levels for glomerular lesions in pregnant women with pre-eclampsia.     

Insulinoma in a third-trimester pregnant woman combined with pre-eclampsia: A case report and review of the diagnostic strategies

Insulinomas are rare neuroendocrine tumors with an incidence of 4 per 1 000 000 person-years, being even rarer during pregnancy. During pregnancy most cases are recognized or become symptomatic during the first trimester.

A 29-year-old woman, primigravida, was hospitalized in the 38th gestational week due to slurred speech, weakness and slow reaction patterns. An electroencephalogram and computed tomography scan of the brain and blood samples were normal. Blood pressure was 170–145/110–95 mmHg, albuminuria was moderate and there was moderate edema of the ankles. Labor started spontaneously the third day, 62 h after of hospitalization, and the patient gave birth to a healthy girl with no neonatal problems. Fourteen hours after delivery, the patient became comatose and developed universal clonic seizures. At the same time plasma glucose was <1.1 mmol/l and the patient responded immediately to intravenous glucose. The patient was managed with frequent small meals and continuous intravenous glucose. Postpartum testing was consistent with insulinoma and diazoxide treatment was initiated. Endoscopic ultrasound with biopsy showed an insulinoma in the head of the pancreas. During surgical exploration, four separate insulinomas were removed from the head of the pancreas. The hypoglycemic episodes resolved and the glucose levels normalized.

Following biochemical diagnosis of insulinoma, diagnostic imaging procedures encountered include endoscopic ultrasonography, magnetic resonance imaging and digital subtraction angiography. Of isotopic procedures, somatostatin receptor scintigraphy (Octreoscan) and newer receptor binding ligands can be used in non-pregnant women. Intraoperative ultrasonography seems mandatory.

The present case demonstrates that seizure disorders in non-diabetic pregnant women may be caused by hyperinsulinemia-induced hypoglycemia due to insulinoma.     

葛根素治疗子痫前期大鼠的疗效观察

目的探讨葛根素对子痫前期大鼠的治疗效果。方法选取SD雌性孕鼠共30只,随机分为正常组、子痫前期组和葛根素组(每组10只)。于孕14d,分别给子痫前期组和葛根素组大鼠尾静脉注入内毒素(1.0μg/kg),建立子痫前期模型,葛根素组大鼠同时给予腹腔注射葛根素注射液(30mg·kg-1·d-1)治疗;正常组大鼠尾静脉注入等量生理盐水。孕第8、15、19天测定各组大鼠24h尿蛋白含量;孕第10、15、19天测定各组大鼠心率、血压;孕第21天用硝酸还原酶法测定各组大鼠血浆一氧化氮(NO)浓度。结果(1)葛根素组、子痫前期组、正常组大鼠24h尿蛋白含量(孕第19天尿蛋白含量-孕第8天尿蛋白含量)分别为(73±20)、(464±57)、(140±12)μg,3组两两比较,差异有统计学意义(P<0.01)。(2)3组大鼠血压(孕第19天血压-孕第10天血压)比较,差异也有统计学意义(P<0.01)。(3)3组大鼠心率(孕第19天心率-孕第10天心率)比较,差异无统计学意义(P>0.05)。(4)孕第21天,血浆NO浓度正常组为(158±31)mmol/L,子痫前期组为(49±36)mmol/L,葛根素组为(162±14)mmol/L,子痫前期组分别与其他两组比较,差异均有统计学意义(P<0.01)。结论葛根素可以提高子痫前期模型大鼠体内NO水平,降低血压和尿蛋白含量,对心率没有明显影响。