Cytotoxicity of inorganic mercury to the liver of two species, Anabas tesludineus and Sprague Dawley male rat was evaluated. Distribution kinetics of this metal in the different hepatic subcellular fractions were foll...Cytotoxicity of inorganic mercury to the liver of two species, Anabas tesludineus and Sprague Dawley male rat was evaluated. Distribution kinetics of this metal in the different hepatic subcellular fractions were followed for 48 h after a single injection of [203Hg] mercuric nitrate at a dose of 4mg/kg b.w. Interaction of this metal with protein, DNA and RNA was also studied. In rat, nuclear and lysosomal fractions showed a significant increase in the protein content, while in fish, the amount of protein increased in all fractions except microsome. Comparatively more mercury was bound to protein in fish during the later phase of treatment. Retention of mercury in nuclear DNA of rat gradually declined from 15 min to 48 h of treatment, while, mitochondria! DNA binding to mercury increased from 15 min to 2 h of post injection and then declined in the later phase of the experiment. Such a biphasic binding pattern of mercury was shown by both the nuclear and mitochondrial DNA of the fish. The nuclear RNA of rat and mitochondrial and cytosolic RNA of both test species also showed a biphasic pattern of mercury binding, however, with a higher rate of binding in fish at the later phase of the experiment. The present study thus highlights that (a) mercury follows a definite distribution pattern in the subcellular fractions of the liver in both animal species, (b) cytosol is the major site of mercury accumulation.展开更多
Earthworms have the ability to accumulate of heavy metals, however, there was few studies that addressed the metals in earthworm at subcellular levels in fields. The distributions of metals （Cd, Cu, Zn, and Pb） in s...Earthworms have the ability to accumulate of heavy metals, however, there was few studies that addressed the metals in earthworm at subcellular levels in fields. The distributions of metals （Cd, Cu, Zn, and Pb） in subcellular fractions （cytosol, debris, and granules） of earthworm Metaphire californica were investigated. The relationship between soil metals and earthworms were analyzed to explain its high plasticity to inhabit in situ contaminated soil of Hunan Province, south China. The concentration of Cd in subcellular compartments showed the same pattern as Cu in the order of cytosol 〉 debris 〉 granules. The distribution of Zn and Pb in earthworms indicated a similar propensity for different subcellular fractions that ranked as granules 〉 debris 〉 cytosol for Zn, and granules 〉 cytosol 〉 debris for Pb. The internal metal concentrations in earthworms increased with the soil metals （p 〈 0.05）. Significant positive correlations were found between soil Cd and Cd concentrations in cytosol and debris （p 〈 0.01）. Moreover, the soil Pb concentration significantly influenced the Pb concentrations in cytosol and debris （p 〈 0.01）, similar to that of Cd. The soil Cu concentrations was only associated with the Cu in granules （p 〈 0.05）. Soil Zn concentrations correlated with the Zn concentrations in each subcellular fraction （p 〈 0.05）. Our results provide insights into the variations of metals partitioning in earthworms at subcellular levels and the relationships of soil metals, which could be one of the detoxiflcation strategies to adapt the long-term contaminated environment.展开更多
文摘Cytotoxicity of inorganic mercury to the liver of two species, Anabas tesludineus and Sprague Dawley male rat was evaluated. Distribution kinetics of this metal in the different hepatic subcellular fractions were followed for 48 h after a single injection of [203Hg] mercuric nitrate at a dose of 4mg/kg b.w. Interaction of this metal with protein, DNA and RNA was also studied. In rat, nuclear and lysosomal fractions showed a significant increase in the protein content, while in fish, the amount of protein increased in all fractions except microsome. Comparatively more mercury was bound to protein in fish during the later phase of treatment. Retention of mercury in nuclear DNA of rat gradually declined from 15 min to 48 h of treatment, while, mitochondria! DNA binding to mercury increased from 15 min to 2 h of post injection and then declined in the later phase of the experiment. Such a biphasic binding pattern of mercury was shown by both the nuclear and mitochondrial DNA of the fish. The nuclear RNA of rat and mitochondrial and cytosolic RNA of both test species also showed a biphasic pattern of mercury binding, however, with a higher rate of binding in fish at the later phase of the experiment. The present study thus highlights that (a) mercury follows a definite distribution pattern in the subcellular fractions of the liver in both animal species, (b) cytosol is the major site of mercury accumulation.
基金supported by the National Natural Science Foundation of China(No.41471410)the Key Beijing Discipline of Ecology(No.XK10019440)
文摘Earthworms have the ability to accumulate of heavy metals, however, there was few studies that addressed the metals in earthworm at subcellular levels in fields. The distributions of metals （Cd, Cu, Zn, and Pb） in subcellular fractions （cytosol, debris, and granules） of earthworm Metaphire californica were investigated. The relationship between soil metals and earthworms were analyzed to explain its high plasticity to inhabit in situ contaminated soil of Hunan Province, south China. The concentration of Cd in subcellular compartments showed the same pattern as Cu in the order of cytosol 〉 debris 〉 granules. The distribution of Zn and Pb in earthworms indicated a similar propensity for different subcellular fractions that ranked as granules 〉 debris 〉 cytosol for Zn, and granules 〉 cytosol 〉 debris for Pb. The internal metal concentrations in earthworms increased with the soil metals （p 〈 0.05）. Significant positive correlations were found between soil Cd and Cd concentrations in cytosol and debris （p 〈 0.01）. Moreover, the soil Pb concentration significantly influenced the Pb concentrations in cytosol and debris （p 〈 0.01）, similar to that of Cd. The soil Cu concentrations was only associated with the Cu in granules （p 〈 0.05）. Soil Zn concentrations correlated with the Zn concentrations in each subcellular fraction （p 〈 0.05）. Our results provide insights into the variations of metals partitioning in earthworms at subcellular levels and the relationships of soil metals, which could be one of the detoxiflcation strategies to adapt the long-term contaminated environment.
