摘要

In aquatic ecosystems, the complex mixture of pollutants may mediate the formation of free radicals and cause oxidative damage to the biota. Yuriria Lake (a Ramsar site in Central Mexico) receives input of wastewater from its tributaries, agricultural runoff, and municipal discharge. We studied the lipid peroxidation (LPO), antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), and histopathology of gill and liver of the native fish Goodea atripinnis in Yuriria Lake. Results were compared to a control group of fish cultivated in the laboratory. LPO, SOD, and CAT showed no significant differences compared to controls, but GPx showed greater and significant differences in both tissues. Three class sizes were identified; organisms of classes I and II had slight vasocongestion in the liver as compared to controls. Hepatocytes of class III showed cytoplasmic vacuolization, cellular disorganization, and the liver showed marked fibrosis compared to controls. Gills of controls and classes I and II showed no damage in gill filaments. Tissue damage in class III included hypertrophy, loss of the typical morphology, and edema in the gill filaments. The longer exposure of older organisms to Yuriria Lake conditions may have resulted in their poorer health condition. En los ecosistemas acu芍ticos, la mezcla compleja de contaminantes presente puede mediar la producci車n de radicales libres y causar da o por estr谷s oxidativo a la biota. La laguna de Yuriria (sitio RAMSAR en la parte central de M谷xico) recibe aguas residuales de sus afluentes, escorrent赤as agr赤colas y descargas municipales. Se estudi車 la peroxidaci車n lip赤dica (LPO), las enzimas antioxidantes super車xido dismutasa, (SOD), catalasa (CAT) y glutati車n peroxidasa (GPx); y la histopatolog赤a de las branquias e h赤gado del pez nativo Goodea atripinnis en la Laguna de Yuriria. Los resultados obtenidos fueron comparados con un grupo control de peces cultivados en laboratorio. La LPO, SOD y CAT no mostraron diferencia significativa en comparaci車n con los controles; pero la GPx mostr車 diferencias significativas para ambos tejidos. Se identificaron tres clases de talla; los organismos de la clase I y II tuvieron una ligera vasocongesti車n en el h赤gado en comparaci車n con los controles. Los hepatocitos de la clase III mostraron vacuolizaci車n citopl芍smica, desorganizaci車n celular y el h赤gado mostr車 una marcada fibrosis. Las branquias de los organismos control y de las clases I y II no mostraron da o en sus filamentos. El da o tisular en los organismos de la clase III incluy車 hipert

全文