Contenido y distribución de metales en suelos ácuicos de la planicie costera bonaerense

Se aporta información sobre los factores que influyen en la concentración y el particionamiento de metales pesados en suelos de la planicie costera del noreste bonaerenseFacultad de Ciencias Naturales y Muse

Hyperactivity and altered mRNA isoform expression of the Cl¯/HCO3¯ anion-exchanger in the hypertrophied myocardium

Objective: The aim was to examine the regulation of the cardiac Na+-independent Cl¯/HCO3¯ exchanger (AE) mRNA isoform expression in association to the enhanced AE activity in the hypertrophied myocardium of spontaneously hypertensive rats (SHR). Methods: AE activity was determined by the initial rates of the pHi recovery from imposed intracellular alkalinization (forward mode of exchange) and the pHi rise induced by Cl¯ removal (reverse mode). Net HCO3¯ (JHCO3¯) efflux and influx were respectively determined. AE mRNA isoforms were analyzed by Northern blot with specific probes to detect AE1, AE2 and AE3 mRNAs. Results: Initial JHCO3¯ efflux after imposed alkaline load (pHi≅7.5) was higher in SHR than in normotensive WKY rats (3.01±0.33, n=7, vs. 0.64±0.29 mM/min, n=5, PHCO3¯ influx induced by Cl¯ deprivation was also increased in SHR, 4.24±0.56 mM/min (n=10) versus 2.31±0.26 (n=10, P<0.05) in WKY. In arbitrary units, the 4.1-kb AE1 mRNA decreased in SHR (0.15±0.01, n=7) compared to WKY (0.29±0.06, n=7, P<0.05), whereas the 3.6-kb mRNA did not change. AE2 mRNAs were similarly expressed in WKY and SHR. Cardiac specific AE3 (cAE3) mRNA decreased in SHR, 1.10±0.16 arbitrary units (n=8) versus 1.79±0.24, (n=8, P<0.05) in WKY. Full length AE3 (flAE3) mRNA increased from 0.69±0.06 (WKY, n=8) to 1.25±0.19 arbitrary units in SHR (n=8, P<0.05). Conclusions: The increase in flAE3 mRNA expression in cardiac tissue from the SHR is an adaptive change of the hypertrophied myocardium that might be in connection with the increased activity of the AE.Facultad de Ciencias MédicasCentro de Investigaciones Cardiovasculare

Hyperactivity and altered mRNA isoform expression of the Cl¯/HCO3¯ anion-exchanger in the hypertrophied myocardium

Objective: The aim was to examine the regulation of the cardiac Na+-independent Cl¯/HCO3¯ exchanger (AE) mRNA isoform expression in association to the enhanced AE activity in the hypertrophied myocardium of spontaneously hypertensive rats (SHR). Methods: AE activity was determined by the initial rates of the pHi recovery from imposed intracellular alkalinization (forward mode of exchange) and the pHi rise induced by Cl¯ removal (reverse mode). Net HCO3¯ (JHCO3¯) efflux and influx were respectively determined. AE mRNA isoforms were analyzed by Northern blot with specific probes to detect AE1, AE2 and AE3 mRNAs. Results: Initial JHCO3¯ efflux after imposed alkaline load (pHi≅7.5) was higher in SHR than in normotensive WKY rats (3.01±0.33, n=7, vs. 0.64±0.29 mM/min, n=5, PHCO3¯ influx induced by Cl¯ deprivation was also increased in SHR, 4.24±0.56 mM/min (n=10) versus 2.31±0.26 (n=10, P<0.05) in WKY. In arbitrary units, the 4.1-kb AE1 mRNA decreased in SHR (0.15±0.01, n=7) compared to WKY (0.29±0.06, n=7, P<0.05), whereas the 3.6-kb mRNA did not change. AE2 mRNAs were similarly expressed in WKY and SHR. Cardiac specific AE3 (cAE3) mRNA decreased in SHR, 1.10±0.16 arbitrary units (n=8) versus 1.79±0.24, (n=8, P<0.05) in WKY. Full length AE3 (flAE3) mRNA increased from 0.69±0.06 (WKY, n=8) to 1.25±0.19 arbitrary units in SHR (n=8, P<0.05). Conclusions: The increase in flAE3 mRNA expression in cardiac tissue from the SHR is an adaptive change of the hypertrophied myocardium that might be in connection with the increased activity of the AE.Facultad de Ciencias MédicasCentro de Investigaciones Cardiovasculare

Análisis ambiental del partido de La Plata : Aportes al ordenamiento territorial

Este estudio brinda información sobre, clima, infraestructura de comunicaciones, topografía, hidrología superficial, geomorfología, características de los suelos y su aptitud agropecuaria-forestal e ingenieril, degradación de suelos por actividades extractivas, uso actual de la tierra, riesgos geológicos y planeamiento ambiental del partido de La Plata. Tal información esta destinada a técnicos del municipio, asi como a entes provinciales y a la actividad privada, aportando ademas a la difusión del conocimiento en diferentes niveles del sistema educativo.Facultad de Ciencias Naturales y Muse

Análisis ambiental del partido de La Plata : Aportes al ordenamiento territorial

Este estudio brinda información sobre, clima, infraestructura de comunicaciones, topografía, hidrología superficial, geomorfología, características de los suelos y su aptitud agropecuaria-forestal e ingenieril, degradación de suelos por actividades extractivas, uso actual de la tierra, riesgos geológicos y planeamiento ambiental del partido de La Plata. Tal información esta destinada a técnicos del municipio, asi como a entes provinciales y a la actividad privada, aportando ademas a la difusión del conocimiento en diferentes niveles del sistema educativo.Facultad de Ciencias Naturales y Muse

Contenido de metales pesados en suelos hidromórficos

Se estudiaron contenidos metálicos en concreciones de hierro-manganeso y carbonáticas de suelos hidromórficos del nordeste bonaerenseFacultad de Ciencias Naturales y Muse

Suelos de humedales afectados por contaminación hídrica, Argentina

Fil: Camilión, María Cecilia. Instituto de Geomorfología y Suelos, Universidad Nacional de La PlataFil: Hurtado, Martín Adolfo. Instituto de Geomorfología y Suelos, Universidad Nacional de La PlataFil: Silva, Mario Marcelo da. Instituto de Geomorfología y Suelos, Universidad Nacional de La PlataFil: Boff, Laura. Instituto de Geomorfología y Suelos, Universidad Nacional de La Plat

Positive chronotropic effect of Bay K 8644: participation of endogenous norepinephrine

The chronotropic effect of Bay K 8644, a dihydropyridine known to increase the slow inward current, was studied in spontaneously beating rat atria. Increases in atrial rate were concentration-dependent and the maximal increase (106 ± 10 beats/min) was obtained at 3 × 10⁻⁶ mol/l. Reserpine pretreatment, or propranolol 3 × 10⁻⁷ mol/l, or propranolol plus prazosin 10⁻⁶ mol/l decreased the maximum chronotropic effect of Bay K 8644 by about 60%. Blockade of the removal mechanisms of catecholamines (hydrocortisone 3 × 10⁻⁵ mol/l plus cocaine 10⁻⁵ mol/1) did not prevent the chronotropic effect of the compound. Exposure to Bay K 8644 increased the spontaneous outflow of tritium from atria preloaded with [3H]-norepinephrine by 30%. The results indicate that Bay K 8644 produces positive chronotropic effects through two mechanisms: a direct one and an indirect mechanism that involves the participation of norepinephrine released from sympathetic nerve endings.Centro de Investigaciones Cardiovasculare

Copper, lead and zinc distribution in soils and sediments of the south-western coast of the Rio de la Plata estuary

Background, Aim and Scope: The compositional study of suspended matter in water from rivers of different latitudes and climates has revealed that the fine fraction reflects both substrate lithology from source areas or topsoil composition along the course. Metal distribution patterns are also strongly related to the clay mineral fate in fluvial aquatic systems. For the particular case of the coastal area of the Río de la Plata estuary in South America, previous studies have, on the one hand, focused on the analysis of distribution patterns of heavy metals in bottom river sediments and, on the other hand, on the assessment of metal contents in topsoils. The present study was conducted to evaluate the Cu, Pb and Zn distribution in soils and sediments from four drainage basins crossing two differentiated geomorphologic units composed of unconsolidated materials and to understand the metal behaviour. Methods: Data used included the existent, self-produced soil and sediment data sets (grain size, organic matter and Cu, Pb and Zn contents from 124 samples). Analyses were performed by using standardised methods: grain size analysis by sieving and settling; organic matter content based on the reduction of dichromate ion followed by titration; metal content by atomic absorption spectrophotometry following acid digestion. Results and Discussion. The average (% w/w) clay and organic matter content were 45.9 ± 17.1 and 1.5 ± 1.7 for sediments and 32.0 ± 19.8, and 7.5 ± 7.6 for soils, respectively. The raw mean metal concentrations (mg-kg-1 dry weight) for sediments and soils were: Cu: 28.02 ± 27.28, 32.08 ± 21.64; Pb: 32.08 ± 46.94, 68.44 ± 69.25 and Zn: 83.09 ± 150.33, 118.22 ± 74.20, respectively. A good correlation for each clay-normalised metal concentration was found between soil and sediments using regression analysis considering average data for each basin sampling site (r > 0.89, p < 0.05). A comparison between metal concentration levels taking into account geomorphologic units by a t independent sample test showed significant differences for the normalised soil-sediment metal data (p < 0.001), responding to differences in grain size, clay mineralogy, organic matter and neoformed Fe-Mn oxide composition. Conclusion, Recommendation and Outlook: A clear parenthood between the topsoils and the bottom sediments in the study area was found. The Argiudolls from the inner zone are frequently affected by rainwater erosion, which washes the fine materials with sorbed metals and carries them to the streams. These watercourses reach the flat coastal plain, where soil flooding and bottom sediment depositional processes predominate. Here, both soils and bottom sediments are enriched in clay, organic matter and metals. The topography and lithology, under the environmental conditions of a temperate and humid climate control the fate of metals within these small basins. The influence of the physical media on the distribution and fate of pollutants should not be minimised in the understanding of the governing processes from natural systems.Centro de Investigaciones en Suelos y Agua de Uso AgropecuarioCentro de Investigaciones GeológicasCentro de Investigaciones del Medioambient