Asunto(s)
Cobre/toxicidad , Daphnia/fisiología , Zinc/toxicidad , Animales , Cobre/análisis , Zinc/análisisRESUMEN
To determine the absorption, organ distribution, and retention of organically bound cadmium (Cd) and the effects of dietary zinc (Zn) on Cd metabolism, groups of mice were fed five different diets. The organic Cd used in the diets was in the form of lyophilized oyster (Crassostrea virginica) that had accumulated radiolabeled 109Cd through a plankton food chain. The mice were fed either a standard basal mouse diet (AIN-76) or diets containing five or eight times the Zn concentration of the basal diet. The source of Zn was either oyster tissue or ZnCO3. The concentration of organic and inorganic Cd provided a dose of approximately 0.4 mg/kg. Diets prepared from oyster tissue probably contained all of the Cd and 85% of the Zn in organic form. Diets prepared with inorganic metals contained about the same Cd and Zn concentrations as the diets prepared with oyster. There was very little difference between the retention of Cd by mice that ingested organic (oyster bound) Cd and those fed inorganic Cd (CdCl2). However, when the Cd retained in the intestine was excluded, retention of organic Cd was significantly greater than that of inorganic Cd. The organ distribution of Cd differed significantly according to the chemical form of Cd fed (organic or inorganic) and the Zn level in the diet. The kidneys of mice fed organically bound Cd retained a higher percentage of the metal than the kidneys of those fed inorganic Cd. On the other hand, the livers of animals fed a low-Zn diet retained a higher percentage of the Cd than the livers of those fed a high-Zn diet, regardless of the dietary source of Cd.
Asunto(s)
Cadmio/metabolismo , Radioisótopos , Absorción , Animales , Dieta , Interacciones Farmacológicas , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Ratones , Ostreidae , Distribución Tisular , Zinc/farmacologíaRESUMEN
Trachelomonas kolii sp. nov., a member of the Euglenophyta, was the causative agent of red snow near Mt. Bachelor, Oregon. The cells are uniflagellate or without flagella and, in general, exhibit the characteristics of the genus Trachelomonas. The lorica, when present, is transparent, elongate, reticulate, and has a funnel-shaped collar at the anterior end. The protoplast is completely filled with red pigment. Red spherical resting stages that appear similar to the resting stages of the ubiquitous snow alga Chlamydomonas nivalis (Bauer) Wille are described.