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Previous clinical studies have shown controversial results regarding the effect of inorganic nitrate supplementation on blood pressure (BP) in older individuals. We performed this systematic review and meta-analysis to assess the effect of inorganic nitrate on BP in older adults.Eligible studies were searched in Cochrane Library, PubMed, Scopus, Web of Science, and Embase. Randomized controlled trials which evaluated the effect of inorganic nitrate consumption on BP in older adults were recruited. The random-effect model was used to calculate the pooled effect sizes.22 studies were included in this meta-analysis. Overall, inorganic nitrate consumption significantly reduced systolic blood pressure (SBP) by -3.90 mmHg (95% confidence interval: -5.23 to -2.57; P 0.001) and diastolic blood pressure (DBP) by -2.62 mmHg (95% confidence interval: -3.86 to -1.37; P 0.005) comparing with the control group. Subgroup analysis showed that the BP was significantly reduced when participants' age≥65, BMI30, or baseline BP in prehypertension stage. And both SBP and DBP decreased significantly after acute nitrate supplementation of a single dose (1 day) or more than 1-week. However, participants with hypertension at baseline were not associated with significant changes in both SBP and DBP. Subgroup analysis of measurement methods showed that only the resting BP group showed a significant reduction in SBP and DBP, compared with the 24-h ambulatory BP monitoring (ABPM) group and daily home BP measurement group.These results demonstrate that consuming inorganic nitrate can significantly reduce SBP and DBP in older adults, especially in whose age ≥ 65, BMI＞30, or baseline BP in prehypertension stage.

Aims Urea transporter B (UTB) is encoded by the SLC14α1 gene, and exerts its activity in the choroid plexus (CP) by regulating [Na+] in the cerebrospinal fluid (CSF) and maintaining normal blood pressure in mice fed on high salt diet. The aim of this study is to investigate the effect of high salt diet on the mean arterial pressure (MAP) in SLC14α1 depletion mice and its possible molecular mechanism. Main methods Adult male mice were divided into four groups: 1) UTB+/+(wild type) mice + normal salt diet (0.3% NaCl, NS); 2) UTB+/+ mice + high salt diet (8% NaCl, HS); 3) UTB−/− (SLC14α1 knockout) mice + NS; 4) UTB−/− mice + HS, each group consisted of 6 mice. The MAP of mice was measured by non-invasive detection method after HS diet for 4 weeks, followed by euthanization for brain and blood collection. Key findings HS significantly elevated the MAP and CSF [Na+] in UTB−/− mice in comparison with wild type mice; however, NS didn't alter the MAP and CSF [Na+] in either wild type mice or UTB−/− mice. HS also induced the expression of ENaC-α and α1-Na+-K+-ATPase in UTB−/− mice as confirmed by RT-PCR and Western blot. Significance These results suggest that the depletion of SLC14α1 gene in mice may contribute to the HS-induced abnormality of sodium transportation in the CSF, and lead to the elevation of MAP, which eventually promote the development of salt-sensitive hypertension.

The mining industry needs to treat large volumes of wastewater highly concentrated in chemical compounds that can adversely affect receiving environments. One promising method of treatment is the use of reverse osmosis to remove most of the dissolved salts. However, the resulting brine reject is a highly saline wastewater that needs further treatment to remove the toxic components, such as selenate, which is a chemical compound of great concern in coal-mining regions. Biological reduction and removal of dissolved selenium from a brine solution was achieved. Microorganisms were enriched from environmental samples collected from two mines, respectively, at different geographic locations through adaptive evolution in the laboratory. Batch treatment of typical brine was tested with two different enrichments with the addition of either of two chemical forms of iron, ferrous chloride or zero valent iron. Successful selenium removal in the presence of high nitrate and sulphate concentrations was achieved with a combination of enriched microorganisms from one particular site and the addition of zero-valent iron. The composition and metabolic potential of the enriched microorganisms revealed Clostridium, Sphaerochaeta, Synergistes and Desulfosporosinus species with the metabolic potential for selenate reduction through the YgfK enzymatic process associated with selenium detoxification.