Background Chloride is speculated to have nephrotoxic properties. In healthy subjects we tested the hypothesis that acute chloride loading with 3% saline would induce kidney injury, which could be prevented with the loop-diuretic furosemide. Methods The study was designed as a randomized, placebo-controlled, crossover study. Subjects were given 3% saline accompanied by either placebo or furosemide. Before, during and after infusion of 3% saline we measured glomerular filtration rate (GFR), fractional excretion of sodium (FE Na ), urinary chloride excretion (u-Cl), urinary excretions of aquaporin-2 (u-AQP2) and epithelial sodium channels (u-ENaC γ ), neutrophil gelatinase-associated lipocalin (u-NGAL) and kidney injury molecule-1 (u-KIM-1) as marker of kidney injury and vasoactive hormones: renin (PRC), angiotensin II (p-AngII), aldosterone (p-Aldo) and arginine vasopressin (p-AVP). Four days prior to each of the two examinations subjects were given a standardized fluid and diet intake. Results After 3% saline infusion u-NGAL and KIM-1 excretion increased slightly (u-NGAL: 17 ± 24 during placebo vs. -7 ± 23 ng/min during furosemide, p = 0.039, u-KIM-1: 0.21 ± 0.23 vs − 0.06 ± 0.14 ng/ml, p <  0.001). The increase in u-NGAL was absent when furosemide was given simultaneously, and the responses in u-NGAL were not significantly different from placebo control. Furosemide changed responses in u-KIM-1 where a delayed increase was observed. GFR was increased by 3% saline but decreased when furosemide accompanied the infusion. U-Na, FE Na , u-Cl, and u-osmolality increased in response to saline, and the increase was markedly pronounced when furosemide was added. FE K decreased slightly during 3% saline infusion, but simultaneously furosemide increased FE K . U-AQP2 increased after 3% saline and placebo, and the response was further increased by furosemide. U-ENaC γ decreased to the same extent after 3% saline infusion in the two groups. 3% saline significantly reduced PRC, p-AngII and p-Aldo, and responses were attenuated by furosemide. p-AVP was increased by 3% saline, with a larger increase during furosemide. Conclusion This study shows minor increases in markers of kidney injury after 3% saline infusion Furosemide abolished the increase in NGAL and postponed the increase in u-KIM-1. The clinical importance of these findings needs further investigation. Trial registration (EU Clinical trials register number: 2015–002585-23 , registered on 5th November 2015)

This study demonstrated an augmented BP-lowering effect of NaNO2 in patients with EHT. We observed an antinatriuretic and antidiuretic effect of NaNO2 in both groups, and a decrease in U-ENaCγ, solely in EHT. In both groups, we detected a nonvasopressin mediated decrease in U-AQP2, which is most likely compensatory to the decline in diuresis.

Background and Aims This study examined the acclimation to temperature of two globally invasive species Iris pseudacorus and Lythrum salicaria, which share the same habitat type but differ in morphology. Iris pseudacorus has long vertical leaves, allowing light penetration through the canopy, while L. salicaria has stems with small horizontal leaves, creating significant self-shading. We aimed to build a physiological understanding of how these two species respond to different growth temperatures with regard to growth and gas exchange-related traits over the canopy. Methods Growth and gas exchange-related traits in response to low (15 °C) and high (25 °C) growth temperature regimes were compared. Plants were grown in growth chambers, and light response curves were measured with infrared gas-analyzers after 23-33 days at three leaf positions on each plant, following the vertical light gradient through the canopy. After 37 days of growth, above-ground biomass, photosynthetic pigments and leaf N concentration were determined. Key results The maximum photosynthesis rate was lower in lower leaf positions but did not differ significantly between temperatures. Iris pseudacorus photosynthesis decreased with decreasing leaf position, more so than L. salicaria. This was explained by decreasing N and chlorophyll concentrations towards the leaf base in I. pseudacorus, while pigment concentrations increased towards the lower canopy in L. salicaria. Biomass, shoot height and specific leaf area increased with temperature, more so in I. pseudacorus than in L. salicaria. Light response curves revealed that L. salicaria had a higher degree of shade-acclimation than I. pseudacorus, probably due to self-shading in L. salicaria. Conclusions High temperature decreased C-assimilation at the bottom of the canopy in L. salicaria, while C-assimilation in I. pseudacorus was less affected by temperature. As vegetative growth and flowering was stimulated by temperature, the invasive potential of these species is predicted to increase under global warming.