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1.
Aquat Toxicol ; 64(2): 143-53, 2003 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-12799107

RESUMEN

In the amphibian Pleurodeles waltl, steroid hormones play a key role in sex differentiation. Since cadmium has been reported to block receptors of sex steroid hormones, we analyzed the effects of this heavy metal on Pleurodeles larvae gonadogenesis. At stage 42, larvae die in the presence of 10.9 microM Cd in the rearing tap water, with TL(50) of 46.3 h, but the concentration of 5.5 microM is tolerated for more than 60 days. When used at 5.5 microM cadmium accumulation measured by atomic absorption spectrophotometry (AAS) in total homogenates of larvae at stage 54 (after 77 days of exposure to the heavy metal) reached 58.1 microg/g of dry weight. At stage 54, we did not detect inhibitory effects on gonadogenesis in larvae reared in the presence of 5.5 microM Cd since stage 42. When the exposure to 5.5 microM Cd was lengthened after stage 54, metamorphosis was delayed and could not be completed. When larvae were exposed to 10.9 microM Cd from stage 54, metamorphosis did not occur and gonad development was stopped. Our study demonstrates a lack of a direct effect of cadmium on sex determination-differentiation but a strong inhibitory effect on metamorphosis, which impairs further gonadal development.


Asunto(s)
Cadmio/toxicidad , Gónadas/efectos de los fármacos , Antagonistas de Hormonas/toxicidad , Metamorfosis Biológica/efectos de los fármacos , Organogénesis/efectos de los fármacos , Pleurodeles/crecimiento & desarrollo , Diferenciación Sexual/efectos de los fármacos , Análisis de Varianza , Animales , Relación Dosis-Respuesta a Droga , Contaminantes Ambientales/toxicidad , Femenino , Hormonas Esteroides Gonadales/antagonistas & inhibidores , Larva/efectos de los fármacos , Larva/crecimiento & desarrollo , Dosificación Letal Mediana , Masculino , Pleurodeles/anatomía & histología , Análisis para Determinación del Sexo , Factores de Tiempo
2.
Environ Res ; 87(3): 147-59, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11771929

RESUMEN

This report covers part of the assessment of a site in northern France polluted by industrial metal emissions. Our objectives were to assess the cadmium burden in children aged 8 to 11 years and look for factors that affected it. A cross-sectional population-based study took place in 1996-1997 and included 400 children (200 in the metal-polluted area). The geometric mean of the blood cadmium (CdB) levels of children living on the polluted site was 0.51 microg/L (95% CI=[0.49-0.53]); that of the nonexposed children was 0.47 microg/L (95% CI=[0.45-0.49]) (P<0.01). The geometric mean of the urinary cadmium (CdU) levels of children living on the polluted site was 1.16 microg/g creatinine (95% CI=[1.01-1.34]); that of the nonexposed children was 0.99 microg/g creatinine (95% CI=[0.86-1.14]) (P=0.10). Mean CdB was higher among children within 4 km of a zinc smelter and consuming > or =500 ml of tap water daily (x1.34; 95% CI=[1.14-1.51]) compared with children living more than 4 km away and consuming <500 ml of tap water daily. Independently of this association, consumption of fish and shellfish (> or =once a week vs. or =once daily vs.

Asunto(s)
Intoxicación por Cadmio/epidemiología , Cadmio/sangre , Cadmio/orina , Contaminantes del Suelo/análisis , Contaminantes Químicos del Agua/análisis , Animales , Carga Corporal (Radioterapia) , Intoxicación por Cadmio/sangre , Intoxicación por Cadmio/orina , Niño , Creatinina/orina , Estudios Transversales , Exposición a Riesgos Ambientales , Conducta Alimentaria , Femenino , Peces , Francia/epidemiología , Humanos , Masculino , Metalurgia , Factores de Riesgo , Mariscos , Contaminantes del Suelo/sangre , Contaminantes del Suelo/orina , Verduras , Contaminantes Químicos del Agua/sangre , Contaminantes Químicos del Agua/orina
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