Organic anion transporter 5 renal expression and urinary excretion in rats with vascular calcification

It has been described renal damage in rats with vascular calcification. The organic anion transporter 5 (Oat5) is only expressed in kidney, and its urinary excretion was proposed as potential early biomarker of renal injury. The aim of this study was to evaluate the Oat5 renal expression and its urinary excretion in an experimental model of vascular calcification in comparison with traditional markers of renal injury. Vascular calcification was obtained by the administration of an overdose of vitamin D3 (300,000 IU/kg, b.w., i.m.) to male Wistar rats. Oat5 urinary abundance was evaluated by Western blotting. Traditional markers of renal injury, such as creatinine and urea plasma levels, urinary protein levels, and urinary alkaline phosphatase (AP) activity, were determined using commercial kits. Histology was assessed by hematoxylin/eosin staining. Oat5 renal expression was evaluated by Western blotting and by immunohistochemistry. An increased expression of Oat5 in renal homogenates, in apical membranes, and in its urinary excretion was observed in rats with vascular calcification. The traditional parameters used to evaluate renal function were not modified, with the exception of histology. It is possible to postulate the urinary excretion of Oat5 as a potential noninvasive biomarker of renal injury associated with vascular calcification.Fil: Hazelhoff, Maria Herminia. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bulacio, Romina Paula. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Torres, Adriana Monica. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Closing the gap? Twitter as an instrument for connected representation

In this chapter, we present a typology of the tweeting behaviour of candidates as a means of analysing the extent to which politicians are harnessing the potential of social media to actively interact with their constituents. Our research, which included content analysis of tweets (n = 13,637) from all the Conservative and Labour tweeting candidates during the 2010 U.K. General Election, focused on four aspects of tweets: type (normal post, interaction, retweet, retweet with comment); interaction (with, e.g. a politician, journalist, citizen); function (e.g. updating, promoting, advice giving, debating); and topic. Additionally, a qualitative reading on the use of personal tweets was carried out. By examining candidates’ tweeting behaviour, we show that British politicians still mainly use Twitter as a unidirectional form of communication. They are neglecting the possibility this social network offers for, what we call, connected representation

Visual transients reveal the veridical position of a moving object

The position of a moving object is often mislocalised in the direction of movement. At the input stage of visual processing, the position of a moving object should still be represented veridically, whereas it should become closer to the mislocalised position at a later processing stage responsible for positional judgment. Here, we show that visual transients expose the veridical position of a moving object represented in early visual areas. For example, when a ring is flashed on a moving bar, the part of the bar within the ring is perceived at the veridical position, whereas the part outside the ring is perceived to be ahead of the ring as in the flash-lag effect. Our observations suggest that a filling-in process is triggered at the edges of the flash. This indicates that, in early cortical areas, moving objects are still represented at their veridical positions, and the perceived location is determined by the higher visual areas

Amelioration of mercury nephrotoxicity after pharmacological manipulation of organic anion transporter 1 (Oat1) and multidrug associated resistance protein 2 (Mrp2) with furosemide

Inorganic mercury is a major environmental contaminant. The primary site of mercuryinduced injury is the kidney due to the uptake of Hg(2+) -conjugated organic anions in the proximal tubule, primary across the organic anion transporter 1 (Oat1) at the basolateral membrane. At the luminal side, mercuric ions are eliminated by the multidrug resistanceassociated protein 2 (Mrp2). It was described that furosemide treatment induces up-regulation of Oat1 renal expression. As novel preventive and therapeutic strategies based in pharmacological manipulation of drug transporters are emerging, this study was designed to evaluate the impact of furosemide modulation of Oat1 on the nephrotoxicity induced by HgCl2. Wistar rats were treated with furosemide (6 mg/100 g/ day, s.c.) during 4 days or with HgCl2 (4 mg/kg, i.p.) 18 h before the experiments or with furosemide during 4 days before the HgCl2 injection. Furosemide treatment improved HgCl2-induced tubular injury as assessed by urinary alkaline phosphatase activity, urinary glucose, Oat5 urinary excretion and histopathological studies. Besides, administration of furosemide enhanced mercury urinary excretion, reduced mercury total renal accumulation and increased Mrp2 renal expression. In summary, furosemide improves HgCl2- induced proximal tubule injury up-regulating mercury transporters and thus, increasing renal elimination of the mercuric ions. Hence, pharmacological manipulation of mercury transporters with furosemide might be a preventive strategy to reduce mercury toxicity.Fil: Hazelhoff, Maria Herminia. Universidad Nacional de Rosario. Facultad de Cs.bioquimicas y Farmaceuticas. Departamento de Cs.fisiologicas. Area Farmacologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Trebucobich, Mara S.. Universidad Nacional de Rosario. Facultad de Cs.bioquimicas y Farmaceuticas. Departamento de Cs.fisiologicas. Area Farmacologia; ArgentinaFil: Stoyanoff, Tania Romina. Universidad Nacional del Nordeste. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Chevalier, Alberto A.. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; Argentina. GIHON Laboratorios Químicos; ArgentinaFil: Torres, Adriana Monica. Universidad Nacional de Rosario. Facultad de Cs.bioquimicas y Farmaceuticas. Departamento de Cs.fisiologicas. Area Farmacologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Geochemical dispersion of tin in marine sediments, Mount's Bay, Cornwall

Imperial Users onl

Exploring ‘Expose -a-thons’:Using an 'EXPOSition marATHON' as a way of connecting student projects with local cultural organisations

For over 40 years, The Science Shops of the University of Groningen connect socially relevant questions from non-profit organisationsto research by students. In order to keep reinventing ourselves as a valuable part of the university, I would like to introduce an interactive and challenging activity called: Expose-a-thon

Effect of erythropoietin on mercury-induced nephrotoxicity: Role of membrane transporters

Mercury is a widespread pollutant. Mercuric ions uptake into tubular cells is supported by the Organic anion transporter 1 (Oat1) and 3 (Oat3) and its elimination into urine is through the Multidrug resistance-associated protein 2 (Mrp2). We investigated the effect of recombinant human erythropoietin (Epo) on renal function and on renal expression of Oat1, Oat3, and Mrp2 in a model of mercuric chloride (HgCl2)- induced renal damage. Four experimental groups of adult male Wistar rats were used: Control, Epo, HgCl2, and Epo+HgCl2. Epo (3000 IU/kg, b.w., i.p) was administered 24 h before HgCl2 (4 mg/kg, b.w., i.p). Experiments were performed 18 h after the HgCl2 dose. Parameters of renal function and structure were evaluated. The protein expression of Oat1, Oat3 and Mrp2 in renal tissue was assessed by immunoblotting techniques. Mercury levels were determined by cold vapour atomic absorption spectrometry. Pretreatment with Epo ameliorated the HgCl2-induced tubular injury as assessed by histopathology and urinary biomarkers. Immunoblotting showed that pretreatment with Epo regulated the renal expression of mercury transporters in a way to decrease mercury content in the kidney. Epo pretreatment ameliorates HgCl2-induced renal tubular injury by modulation of mercury transporters expression in the kidneys.Fil: Hazelhoff, Maria Herminia. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Departamento de Ciencias Fisiológicas. Área Farmacología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; ArgentinaFil: Torres, Adriana Monica. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Departamento de Ciencias Fisiológicas. Área Farmacología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentin

Respiratory Control in the Lungfish, Neoceratodus Forsteri (Krefft)

1. Respiratory control has been studied in the lungfish, Neoceratodus forsteri by measuring ventilation (Ve), oxygen uptake (VO2), per cent O2 extraction from water, breathing rates of branchial and aerial respiration and changes in blood gas and pulmonary gas composition during exposure to hypoxia and hypercarbia. 2. Hypoxic water represents a strong stimulus for compensatory increase in both branchial and aerial respiration. Water ventilation increases by a factor of 3 or 4 primarily as a result of increased depth of breathing. 3. The ventilation perfusion ratio decreased during hypoxia because of a marked increase in cardiac output. Hypoxia also increased the fraction of total blood flow perfusing the lung. Injection of nitrogen into the lung evoked no compensatory changes. 4. It is concluded that the chemoreceptors eliciting the compensatory changes are located on the external side facing the ambient water or in the efferent branchial blood vessels. 5. Elevated pCO2 in the ambient water depressed the branchial respiration but stimulated aerial respiration. 6. It is suggested that the primary regulatory effect of the response to increased ambient pCO2 is to prevent CO2 from entering the animal, while the secondary stimulation of air breathing is caused by hypoxic stimulation of chemoreceptors located in the efferent branchial vessels