Low serum selenium in pregnancy is associated with reduced T3 and increased risk of GDM.

Thyroid disorders are the most common endocrine disorders affecting women commencing pregnancy. Thyroid hormone metabolism is strongly influenced by selenium status; however, the relationship between serum selenium concentrations and thyroid hormones in euthyroid pregnant women is unknown. This study investigated the relationship between maternal selenium and thyroid hormone status during pregnancy by utilizing data from a retrospective, cross-sectional study (Maternal Outcomes and Nutrition Tool or MONT study) with cohorts from two tertiary care hospitals in South East Queensland, Australia. Pregnant women (n = 206) were recruited at 26-30 weeks gestation and serum selenium concentrations were assessed using inductively coupled plasma mass spectrometry. Thyroid function parameters were measured in serum samples from women with the lowest serum selenium concentrations (51.2 ± 1.2 µg/L), women with mean concentrations representative of the entire cohort (78.8 ± 0.4 µg/L) and women with optimal serum selenium concentrations (106.9 ± 2.3 µg/L). Women with low serum selenium concentrations demonstrated reduced fT3 levels (P < 0.05) and increased TPOAb (P < 0.01). Serum selenium was positively correlated with fT3 (P < 0.05) and negatively correlated with TPOAb (P < 0.001). Serum fT4 and thyroid-stimulating hormone (TSH) were not different between all groups, though the fT4/TSH ratio was increased in the low selenium cohort (P < 0.05). Incidence of pregnancy disorders, most notably gestational diabetes mellitus, was increased within the low serum selenium cohort (P < 0.01). These results suggest selenium status in pregnant women of South East Queensland may not be adequate, with possible implications for atypical thyroid function and undesirable pregnancy outcomes.

Effect of micronutrient supplements on low-risk pregnancies in high-income countries: a systematic quantitative literature review.

OBJECTIVE: To assess the quantity and focus of recent empirical research regarding the effect of micronutrient supplementation on live birth outcomes in low-risk pregnancies from high-income countries. DESIGN: A systematic quantitative literature review. SETTING: Low-risk pregnancies in World Bank-classified high-income countries, 2019. RESULTS: Using carefully selected search criteria, a total of 2475 publications were identified, of which seventeen papers met the inclusion criteria for this review. Data contributing to nine of the studies were sourced from four cohorts; research originated from ten countries. These cohorts exhibited a large number of participants, stable data and a low probability of bias. The most recent empirical data offered by these studies was 2011; the most historical was 1980. In total, fifty-five categorical outcome/supplement combinations were examined; 67·3 % reported no evidence of micronutrient supplementation influencing selected outcomes. CONCLUSIONS: A coordinated, cohesive and uniform empirical approach to future studies is required to determine what constitutes appropriate, effective and safe micronutrient supplementation in contemporary cohorts from high-income countries, and how this might influence pregnancy outcomes.

Influence of dietary intake and decision-making during pregnancy on birth outcomes.

AIM: This study aimed to examine dietary intake and decision-making in a cohort of pregnant South-East Queensland women to determine compliance with dietary guidelines and the relationships between dietary intake, decision-making and birth outcomes. METHODS: Pregnant women attending maternity services at participating hospitals reported food frequency and motivations using the Maternal Outcomes and Nutrition Tool, a novel digital instrument. Birth outcomes were sourced from hospital records. A cross-sectional cohort design was used to examine the data. RESULTS: Analysis demonstrated suboptimal intake of core food groups; meat and alternatives (median [IQR]) (2.6 [2.0-3.4] serves/day) and grains (3.1 [2.1-4.1]) fell below recommendations; fruit (3.8 [2.5-5.3]) and discretionary foods (3.1 [2.1-4.4]) exceeded them. Hypertensive disorders demonstrated a negative linear relationship with vegetable intake (P = .017). Cultural diversity was significantly associated with decreased birthweight (P = .022) but increased intake of meat and alternatives (3.1 vs 2.6, P < .001) compared to Caucasian women; median intake of meat and alternatives was lower in women who reported smoking in the examined time frame. Smokers were less likely to declare health motives for food selection than non-smokers; smoking and health were inversely associated with increasing maternal age. Food choice was primarily sensory-driven. CONCLUSIONS: This cohort demonstrated poor adherence to dietary guidelines. Culturally and linguistically diverse women and smokers exhibit dietary behaviours which may contribute to suboptimal birth outcomes; targeted nutrition counselling may improve outcomes in these women. These findings highlight the need for transdisciplinary maternity care and provide a foundation for further research aimed at optimising nutrition-related birth outcomes in at-risk groups.

Use of micronutrient supplements in pregnant women of south-east Queensland.

BACKGROUND: Multiple micronutrient supplement use in the Australian pregnant population is rising, despite little evidence of benefit in low-risk women. While some supplement recommendations are grounded in high-quality evidence, others warrant further investigation. This highlights a research gap regarding appropriate use of supplements during pregnancy in the Australian population. AIMS: To describe micronutrient supplement use during pregnancy in the context of current evidence and national recommendations in a population of south-east Queensland women. MATERIAL AND METHODS: A cross-sectional observational design was used to examine data gathered from pregnant women aged 16-44 years residing in south-east Queensland, Australia. Women were recruited to the study between 23 May 2016 and 30 September 2017. RESULTS: Pregnancy multivitamin use was declared by 42% of the cohort, with 26.8% declaring multivitamins in combination with individual micronutrients and 9.8% declaring specific micronutrient supplement use. Nulliparous women were more likely to declare use of supplements than their multiparous peers (adjusted odds ratio (aOR) 1.938, 95% CI 1.053-3.571, P = 0.034); smoking (aOR 2.717, 95% CI 1.011-7.302, P = 0.047) and low socio-economic status were associated with no supplement use (aOR 2.451, 95% CI 1.010-5.949, P = 0.048). CONCLUSIONS: Current recommendations regarding micronutrient supplements throughout pregnancy are based on varying degrees of evidence, resulting in supplement advice of poor cohesion and consistency. Adherence to micronutrient supplement recommendations in the peri-conception period in this population was poor; second and third trimester supplement use was high. Contemporary empirical research is required to determine what constitutes appropriate supplementation in high-income regions and the populations they will benefit most.

Essential Mineral Intake During Pregnancy and Its Association With Maternal Health and Birth Outcomes in South East Queensland, Australia.

Micronutrient supplements are often recommended during pregnancy, yet their role and necessity remain poorly understood in the Australian population. This study aimed to determine the essential mineral intake of a population of pregnant women in South East Queensland and investigate the effects of supplements on their micronutrient status and birth outcomes. Women completing the Oral Glucose Tolerance Test at two South East Queensland hospitals between 180 and 210 days gestation provided fasting blood samples and dietary data using the Maternal Outcomes and Nutrition Tool (n = 127). Birth outcomes were sourced from medical records. Serum elemental profiles were determined by inductively coupled plasma mass spectrometry (ICP-MS) analysis. Intake of 8 essential minerals was compared with Australian dietary recommendations; matched serum mineral levels were compared with the current Queensland pregnancy reference ranges. Data were examined using cross-sectional cohort design and independent sample t-tests. Supplement use had no significant influence on serum values of trace elements or the incidence of hypertensive disorders, gestational diabetes, preterm birth or infant birthweight. Dietary selenium, zinc and iodine were significantly higher in women birthing beyond 41 completed weeks; selenium (P = .026) and zinc (P = .034) both made unique contributions to the regression models when controlling for confounders. Women exhibited adequate to excessive serum micronutrient levels compared with pregnancy reference ranges, a finding consistent with dietary intake calculations. Data suggest that excessive essential mineral intake contributed to prolonged pregnancy in this cohort, supporting previous studies in this population. Further research is required to determine individual needs and eliminate the potential for harm before recommending pregnancy supplements.

Maternal selenium deficiency during pregnancy in mice increases thyroid hormone concentrations, alters placental function and reduces fetal growth.

KEY POINTS: Inappropriate intake of key micronutrients in pregnancy is known to alter maternal endocrine status, impair placental development and induce fetal growth restriction. Selenium is an essential micronutrient required for the function of approximately 25 important proteins. However, the specific effects of selenium deficiency during pregnancy on maternal, placental and fetal outcomes are poorly understood. The present study demonstrates that maternal selenium deficiency increases maternal triiodothyronine and tetraiodothyronine concentrations, reduces fetal blood glucose concentrations, and induces fetal growth restriction. Placental expression of key selenium-dependent thyroid hormone converting enzymes were reduced, whereas the expression of key placental nutrient transporters was dysregulated. Selenium deficiency had minimal impact on selenium-dependent anti-oxidants but increased placental copper concentrations and expression of superoxide dismutase 1. These results highlight the idea that selenium deficiency during pregnancy may contribute to thyroid dysfunction, causing reduced fetal growth, that may precede programmed disease outcomes in offspring. ABSTRACT: Selenium is a trace element fundamental to diverse homeostatic processes, including anti-oxidant regulation and thyroid hormone metabolism. Selenium deficiency in pregnancy is common and increases the risk of pregnancy complications including fetal growth restriction. Although altered placental formation may contribute to these poor outcomes, the mechanism by which selenium deficiency contributes to complications in pregnancy is poorly understood. Female C57BL/6 mice were randomly allocated to control (>190 µg kg-1 , n = 8) or low selenium (<50 µg kg-1 , n = 8) diets 4 weeks prior to mating and throughout gestation. Pregnant mice were killed at embryonic day 18.5 followed by collection of maternal and fetal tissue. Maternal and fetal plasma thyroid hormone concentrations were analysed, as was placental expression of key selenoproteins involved in thyroid metabolism and anti-oxidant defences. Selenium deficiency increased plasma tetraiodothyronine and triiodothyronine concentrations. This was associated with a reduction in placental expression of key selenodependent deiodinases, DIO2 and DIO3. Placental expression of selenium-dependent anti-oxidants was unaffected by selenium deficiency. Selenium deficiency reduced fetal glucose concentrations, leading to reduced fetal weight. Placental glycogen content was increased within the placenta, as was Slc2a3 mRNA expression. This is the first study to demonstrate that selenium deficiency may reduce fetal weight through increased maternal thyroid hormone concentrations, impaired placental thyroid hormone metabolism and dysregulated placental nutrient transporter expression. The study suggests that the magnitude of selenium deficiency commonly reported in pregnant women may be sufficient to impair thyroid metabolism but not placental anti-oxidant concentrations.

Design, development, and evaluation of the Maternal Outcomes and Nutrition Tool (MONT).

Suboptimal nutrition has been largely associated with poorer perinatal outcomes. However, an inability to compare data between biologically and geographically diverse cohorts has complicated determination of the role of diet in such conditions. The aim of this paper is to describe the design, development, and evaluation of the Maternal Outcomes and Nutrition Tool (MONT), a novel cross-cultural digital dietary data collection tool. The tool was modelled on previously validated food frequency questionnaires and designed for exclusive administration in the digital environment, featuring minimal language and emphasis on images. Participants were recruited by both passive and active means. A total of 502 women were recruited; descriptive statistics were used to describe the cohort. Pregnant women constituted the majority of subjects recruited (n = 376, 74.9%), 63% of which were nulliparous. Women were recruited from 13 ethnicities and 20 countries of birth. Of the 341 women who commenced the surveys (68%), 114 submitted complete datasets (33.5%). Maintenance and recruitment costs equated to $5.64 per completion. Total processing and analysis time for the pilot dataset equated to 12 s per survey. The MONT was used successfully by women from a variety of continents and cultures and proved to be practical and economical in terms resource management.

Ozone therapy for the treatment of chronic wounds: A systematic review.

Chronic wounds present a significant burden to the health care system and the patient. Ozone therapy has been proposed as a treatment for chronic wounds, potentially acting by eliciting mild oxidative stress or disinfection. The purpose of this systematic review is to evaluate the potential benefits and harms of ozone therapy as an advanced care intervention for chronic wounds. Studies were extracted from Google Scholar, PubMed, the Cochrane Library, and reference lists. General inclusion criteria included English-language randomised human trials reporting the use of ozone therapy in the topical treatment of chronic wounds. Primary outcome data included the extent of chronic wound healing, and secondary outcomes included adverse effects. Studies were assessed for level of bias and data quality. Nine studies (n = 453 patients) matched the inclusion criteria and underwent meta-analysis. Overall, there was a significant improvement in wound closure with ozone therapy. Results consistently favour the application of ozone as a treatment for chronic wounds; however, there is no conclusive evidence of ozone therapy as superior compared with standard treatments. Compared with standard care, ozone therapy as an advanced wound care treatment may improve the proportion of chronic wounds healed in a shorter amount of time, but further research is required.

Selective inhibition of endogenous antioxidants with Auranofin causes mitochondrial oxidative stress which can be countered by selenium supplementation.

Auranofin is a thiol-reactive gold (I)-containing compound with potential asa chemotherapeutic. Auranofin has the capacity to selectively inhibit endogenous antioxidant enzymes thioredoxin reductase (TrxR) and glutathione peroxidase (GPx), resulting in oxidative stress and the initiation of a pro-apoptotic cascade. The effect of Auranofin exposure on TrxR and GPx, and the potential for cellular protection through selenium supplementation was examined in the non-cancerous human cell line Swan-71. Auranofin exposure resulted in a concentration dependent differential inhibition of selenoprotein antioxidants. Significant inhibition of TrxR was observed at 20nM Auranofin with inhibition of GPx from 10µM. Significant increases in reactive oxygen species (ROS) were associated with antioxidant inhibition at Auranofin concentrations of 100nM (TrxR inhibition) and 10µM (TrxR and GPx inhibition), respectively. Evaluation of mitochondrial respiration demonstrated significant reductions in routine and maximal respiration at both 100nM and 10µM Auranofin. Auranofin treatment at concentrations of 10µM and higher concentrations resulted in a ∼68% decrease in cellular viability and was associated with elevations in pro-apoptotic markers cytochrome c flux control factor (FCFc) at concentration of 100nM and mitochondrial Bax at 10µM. The supplementation of selenium (100nM) prior to treatment had a generalized protective affect through the restoration of antioxidant activity with a significant increase in TrxR and GPx activity, a significant reduction in ROS and associated improvement in mitochondrial respiration and cellular viability (10µM ∼48% increase). Selenium supplementation reduced the FCFc at low doses of Auranofin (<10µM) however no effect was noted on either FCFc or Bax at concentrations above 10µM. The inhibition of antioxidant systems in non-cancerous cells by Auranofin is strongly dose dependent, and this inhibition can be altered by selenium exposure. Therefore, Auranofin dose and the selenium status of patients are important considerations in the therapeutic use of Auranofin as an agent of chemosensitization.

Review: Effects of maternal micronutrient supplementation on placental function.

Pregnancy is a physiological challenge that may require additional nutritional support. Suboptimal micronutrient intakes and micronutrient deficiencies during pregnancy are a global problem, often leading to poor maternal and child outcomes. Micronutrient supplementation is commonly recommended during pregnancy to support and enhance maternal metabolism. Recent studies suggest that the use of multiple micronutrient supplements may be of benefit during a normal pregnancy and may significantly reduce the risk of preeclampsia, preterm delivery, gestational diabetes, and improve pregnancy outcomes. Given the crucial role that the placenta plays in mediating pregnancy outcomes, it is important to consider the impact of micronutrient supplementation on the mechanisms associated with placental function, as well as maternal and fetal homeostasis. This review will consider the role of key micronutrients in supporting pregnancy and the possible mechanisms by which multiple micronutrients influence placental function and modulate placental oxidative stress and inflammation.

Overexpression of Endogenous Anti-Oxidants with Selenium Supplementation Protects Trophoblast Cells from Reactive Oxygen Species-Induced Apoptosis in a Bcl-2-Dependent Manner.

The human placenta provides life support for the developing foetus, and a healthy placenta is a prerequisite to a healthy start to life. Placental tissue is subject to oxidative stress which can lead to pathological conditions of pregnancy such as preeclampsia, preterm labour and intrauterine growth restriction. Up-regulation of endogenous anti-oxidants may alleviate placental oxidative stress and provide a therapy for these complications of pregnancy. In this study, selenium supplementation, as inorganic sodium selenite (NaSel) or organic selenomethionine (SeMet), was used to increase the protein production and cellular activity of the important redox active proteins glutathione peroxidase (GPx) and thioredoxin reductase (Thx-Red). Placental trophoblast cell lines, BeWo, JEG-3 and Swan-71, were cultured in various concentrations of NaSel or SeMet for 24 h and cell extracts prepared for western blots and enzyme assays. Rotenone and antimycin were used to stimulate mitochondrial reactive oxygen species (ROS) production and induce apoptosis. Trophoblast cells supplemented with 100 nM NaSel and 500 nM SeMet exhibited significantly enhanced expression and activity of both GPx and Thx-Red. Antimycin and rotenone were found to generate ROS when measured by 2',7'-dichlorofluorescein diacetate (DCFDA) assay, and selenium supplementation was shown to reduce ROS production in a dose-dependent manner. Rotenone, 100 µM treatment for 4 h, caused trophoblast cell apoptosis as evidenced by increased Annexin V binding and decreased expression of Bcl-2. In both assays of apoptosis, selenium supplementation was able to prevent apoptosis, preserve Bcl-2 expression and protect trophoblast cells from mitochondrial oxidative stress. This data suggests that selenoproteins such as GPx and Thx-Red have an important role in protecting trophoblast cells from mitochondrial oxidative stress and that selenium supplementation may be important in treating some placental pathologies.

Learning-oriented assessment increases performance and written skills in a second year metabolic biochemistry course.

Assessment plays a critical role in learning and teaching and its power to enhance engagement and student outcomes is still underestimated in tertiary education. The current project considers the impact of a staged redesign of an assessment strategy that emphasized relevance of learning, formative assessment, student engagement, and feedback on student performance, failure rates and overall engagement in the course. Significant improvements in final grades (p < 0.0001) and written performance (p < 0.0001) in the final examination were noted that coincided with increased lecture attendance and overall engagement in the course. This study reinforces the importance of an integrated approach to assessment that includes well developed formative tasks and a continuous summative assessment strategy. © 2016 by The International Union of Biochemistry and Molecular Biology, 44(4):412-420, 2016.

Multiple micronutrient supplementation and birth outcomes: The potential importance of selenium.

A healthy diet and lifestyle is a pre requisite to a healthy pregnancy, however this is often not the case. Many pregnant women are overweight or clinically obese and this has been shown to increase their risk of major complications of pregnancy such a preeclampsia, intrauterine growth retardation, preterm birth and gestational diabetes. An adequate and balanced diet is important, as is the balance between macronutrients such as carbohydrates, fats and protein and the vitamins and essential trace elements needed to support metabolism. In this review, we look at the use of micronutrient supplements during pregnancy and examine the recommendations currently in place to guide the use of these products. We also present evidence that broad-spectrum micronutrients may have a beneficial effect in pregnancy and lower the incidence of preeclampsia and preterm labour, especially in overweight and obese women. Finally we focus on the essential trace element Selenium and present a strong case for its importance in maintaining mitochondrial function during oxidative stress which is generated in the placentae of women experiencing these complications of pregnancy. It can no longer be assumed that women are consuming an adequate and well balanced diet during pregnancy and the use of micronutrient supplements may potentially have positive effects on a healthy start to life. Globally, millions of women are currently taking these products each year and an opportunity exists to systematically determine their beneficial effect.

No effect of modest selenium supplementation on insulin resistance in UK pregnant women, as assessed by plasma adiponectin concentration.

Concern has been expressed recently that Se may increase the risk of type 2 diabetes, but this has not been tested in a randomised-controlled trial (RCT) in pregnant women. We took advantage of having stored plasma samples from the Se in Pregnancy Intervention (SPRINT) RCT of Se supplementation in pregnancy to test the effect of Se supplementation on a marker of insulin resistance in UK pregnant women. Because our blood samples were not fasted, we measured plasma adiponectin concentration, a recognised marker of insulin resistance that gives valid measurements in non-fasted samples, as diurnal variability is minor and there is no noticeable effect of food intake. In SPRINT, 230 primiparous UK women were randomised to treatment with Se (60 µg/d) or placebo from 12 weeks of gestation until delivery. We hypothesised that supplementation with Se at a nutritional level would not exacerbate the fall in adiponectin concentration that occurs in normal pregnancy, indicating the lack of an adverse effect on insulin resistance. Indeed, there was no significant difference between the two groups in the change in adiponectin from 12 to 35 weeks (P=0·938), nor when the analysis was restricted to the bottom or top quartiles of baseline whole-blood Se (P=0·515 and 0·858, respectively). Cross-sectionally, adiponectin concentration was not associated with any parameter of Se status, either at 12 or 35 weeks. It is reassuring that a nutritional dose of Se had no adverse effect on the concentration of adiponectin, a biomarker of insulin resistance, in pregnant women of modest Se status.

Genetic polymorphisms that affect selenium status and response to selenium supplementation in United Kingdom pregnant women.

BACKGROUND: Low selenium status in pregnancy has been associated with a number of adverse conditions. In nonpregnant populations, the selenium status or response to supplementation has been associated with polymorphisms in dimethylglycine dehydrogenase (DMGDH), selenoprotein P (SEPP1) and the glutathione peroxidases [cytosolic glutathione peroxidase (GPx1) and phospholipid glutathione peroxidase (GPx4)]. OBJECTIVE: We hypothesized that, in pregnant women, these candidate polymorphisms would be associated with selenium status in early pregnancy, its longitudinal change, and the interindividual response to selenium supplementation at 60 µg/d. DESIGN: With the use of stored samples and data from the United Kingdom Selenium in Pregnancy Intervention (SPRINT) study in 227 pregnant women, we carried out genetic-association studies, testing for associations between selenium status, its longitudinal change, and response to supplementation and common genetic variation in DMGDH (rs921943), SEPP1 (rs3877899 and rs7579), GPx1 (rs1050450) and GPx4 (rs713041). Selenium status was represented by the concentration of whole-blood selenium at 12 and 35 wk of gestation, the concentration of toenail selenium at 16 wk of gestation, and plasma glutathione peroxidase (GPx3) activity at 12 and 35 wk of gestation. RESULTS: Our results showed that DMGDH rs921943 was significantly associated with the whole-blood selenium concentration at 12 wk of gestation (P = 0.032), which explained ≤2.0% of the variance. This association was replicated with the use of toenail selenium (P = 0.043). In unsupplemented women, SEPP1 rs3877899 was significantly associated with the percentage change in whole-blood selenium from 12 to 35 wk of gestation (P = 0.005), which explained 8% of the variance. In supplemented women, SEPP1 rs3877899 was significantly associated with the percentage change in GPx3 activity from 12 to 35 wk of gestation (P = 0.01), which explained 5.3% of the variance. Selenium status was not associated with GPx1, GPx4, or SEPP1 rs7579. CONCLUSIONS: In agreement with previous studies, we show that the genetic variant rs921943 in DMGDH is significantly associated with selenium status in United Kingdom pregnant women. Notably, our study shows that women who carry the SEPP1 rs3877899 A allele are better able to maintain selenium status during pregnancy, and their GPx3 activity increases more with supplementation, which suggests better protection from low selenium status. The SPRINT study was registered at www.isrctn.com as ISRCTN37927591.

Selenium status in U.K. pregnant women and its relationship with hypertensive conditions of pregnancy.

Dietary intake/status of the trace mineral Se may affect the risk of developing hypertensive conditions of pregnancy, i.e. pre-eclampsia and pregnancy-induced hypertension (PE/PIH). In the present study, we evaluated Se status in U.K. pregnant women to establish whether pre-pregnant Se status or Se supplementation affected the risk of developing PE/PIH. The samples originated from the SPRINT (Selenium in PRegnancy INTervention) study that randomised 230 U.K. primiparous women to treatment with Se (60 µg/d) or placebo from 12 weeks of gestation. Whole-blood Se concentration was measured at 12 and 35 weeks, toenail Se concentration at 16 weeks, plasma selenoprotein P (SEPP1) concentration at 35 weeks and plasma glutathione peroxidase (GPx3) activity at 12, 20 and 35 weeks. Demographic data were collected at baseline. Participants completed a FFQ. U.K. pregnant women had whole-blood Se concentration lower than the mid-range of other populations, toenail Se concentration considerably lower than U.S. women, GPx3 activity considerably lower than U.S. and Australian pregnant women, and low baseline SEPP1 concentration (median 3.00, range 0.90-5.80 mg/l). Maternal age, education and social class were positively associated with Se status. After adjustment, whole-blood Se concentration was higher in women consuming Brazil nuts (P= 0.040) and in those consuming more than two seafood portions per week (P= 0.054). A stepwise logistic regression model revealed that among the Se-related risk factors, only toenail Se (OR 0.38, 95% CI 0.17, 0.87, P= 0.021) significantly affected the OR for PE/PIH. On excluding non-compliers with Se treatment, Se supplementation also significantly reduced the OR for PE/PIH (OR 0.30, 95% CI 0.09, 1.00, P= 0.049). In conclusion, U.K. women have low Se status that increases their risk of developing PE/PIH. Therefore, U.K. women of childbearing age need to improve their Se status.

Chronic nitric oxide synthase inhibition in pregnant rats does not result in placental oxidative stress.

OBJECTIVE: This investigation examined the physiological and biochemical changes in pregnant rats following treatment with the nitric oxide synthase inhibitor, L nitroarginine methyl ester (L-NAME). METHODS: Pregnant and non-pregnant animals were administered L-NAME, and blood pressure and proteinuria were monitored. On day 21 of pregnancy, the animals were euthanized, and fetal and placental weight and number were recorded. Placental tissues were homogenized and assayed for lipid peroxides, protein carbonyls, superoxide dismutase, glutathione peroxidase, and thioredoxin reductase. RESULTS: Significant increases in blood pressure, urinary protein concentrations, and reduced pup weights were observed in pregnant rats treated with L-NAME. There was no significant increase in lipid or protein oxidation after treatment with L-NAME, and no difference was found in the activities of superoxide dismutase, glutathione peroxidase, and thioredoxin reductase. DISCUSSION: The L-nitroarginine methyl ester model of experimental preeclampsia induces a number of the physiological characteristics typical of the human disease however fails to initiate biochemical changes in the placenta that occur during human preeclampsia.