Última modificación: 2012-04-17
Resumen
Introducción:
La exposición prolongada a toxinas cyanobacterianas, como las Microcystinas, presentes en cuerpos de agua dulce o en agua potable es un problema sanitario-ambiental importante.
Los daños causados por la hepatotoxina MC-LR han sido extensamente descriptos en animales, pero hasta el momento no se han encontrado biomarcadores específicos.
Debido a la dificultad en detectar Microystinas en sangre u orina, el objetivo de este trabajo fue la búsqueda de marcadores clínicos en una exposición prolongada a MC-LR en ratones, que podrían ser útiles como biomarcadores de efectos y emplearse como herramientas en estudios de riesgo.
Métodos:
MC-LR fue purificada a partir de florecimientos de Microcystis aeruginosa recolectados del río de La Plata. Se inyectaron intraperitonealmente ratones N:NIH Swiss cada 48 hs durante un mes con dosis de 25 μgMC-LR/kg de peso.
En la sangre de estos ratones y de controles se determinaron los siguientes parámetros Metahemoglobina (MetHb, forma oxidada de hemoglobina), Fosfatasa alcalina (FAL), Aspartato transaminasa (AST), Alanina transaminasa (ALT), Superóxido dismutasa (SOD) e Hidroperóxidos totales (ROOHs).
Resultados, Discusión y Concluciones:
Los niveles plasmáticos de FAL, ALT y AST mostraron aumentos significativos en las muestras de los animales expuestos a MC-LR respecto de los controles. El análisis de los ROOHs plasmáticos reveló un aumento significativo en los ratones expuestos a MC-LR (3,8 ± 1,2 μmol/grproteina) respecto de los controles (1,4 ± 0,6 μmol/grproteina).
Como consecuencia del aumento de ROOHs, se observó un aumento en los valores de MetHb en los animales tratados (14,6 ± 3,8 %MetHb/HbT) respecto de los controles (6,9 ± 3,6 %MetHb/HbT). Además se encontraron alteraciones en los valores de actividad de SOD en los animales expuestos en comparación con el control.
Estos biomarcadores (principalmenteROOHs y MetHb) podrían emplearse en la detección clínica de casos de exposiciones prolongadas que luego serán confirmados en laboratorios especializados por detección de MC-LR.
Citas
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