Protective effect of metallothionein on intracellular pH changes induced by cadmium

Koizumi, Toshiaki; Yokota, Tetsuo; Ohmori, Shigeru; Kumagai, Hiroshi; Suzuki, Kazuo

doi:10.1016/0300-483x(94)02865-r

Cited by 13 publications

(2 citation statements)

References 28 publications

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“…Bacterial pathogens such as Vibrio spp. also express metalloproteases and serine proteases as virulence factors (Koizumi et al, 1995). Molluscan protease inhibitors can directly inactivate extracellular pathogen-secreted proteases reducing the pathogen's virulence (Xue et al, 2006).…”

Section: Interactive Effects Of Cu and P Co2 On Metabolism And Immunementioning

confidence: 99%

Interactive effects of copper exposure and environmental hypercapnia on immune functions of marine bivalves Crassostrea virginica and Mercenaria mercenaria

Ivanina

Hawkins

Sokolova

2016

Fish & Shellfish Immunology

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Estuarine organisms such as bivalves are commonly exposed to trace metals such as copper (Cu) and hypercapnia (elevated CO2 levels) in their habitats, which may affect their physiology and immune function. This study investigated the combined effects of elevated CO2 levels (∼800-2000 μatm PCO2, such as predicted by the near-future scenarios of global climate change) and Cu (50 μg l(-1)) on immune functions of the sediment dwelling hard clams Mercenaria mercenaria and an epifaunal bivalve, the eastern oyster Crassostrea virginica. Clams and oysters were exposed for 4 weeks to different CO2 and Cu levels, and tissue Cu burdens and immune parameters were assessed to test the hypothesis that hypercapnia will enhance Cu uptake due to the higher bioavailability of free Cu(2+) and increase the immunomodulatory effects of Cu. Exposure to Cu stimulated key immune parameters of clams and oysters leading to increased number of circulating hemocytes, higher phagocytosis and adhesion ability of hemocytes, as well as enhanced antiparasitic and antibacterial properties of the hemolymph reflected in higher activities of lysozyme and inhibitors of cysteine proteases. Lysozyme activation by Cu exposure was most prominent in normocapnia (∼400 μatm PCO2) and an increase in the levels of the protease inhibitors was strongest in hypercapnia (∼800-2000 μatm PCO2), but other immunostimulatory effects of Cu were evident in all PCO2 exposures. Metabolic activity of hemocytes of clams and oysters (measured as routine and mitochondrial oxygen consumption rates) was suppressed by Cu exposure likely reflecting lower rates of ATP synthesis and/or turnover. However, this metabolic suppression had no negative effects of the studied immune functions of hemocytes such as phagocytosis or adhesion capacity. Hypercapnia (∼800-2000 μatm PCO2) slightly but significantly enhanced accumulation of Cu in hemocytes, consistent with higher Cu(2+) bioavailability in CO2-acidified water, but had little effect on cellular and humoral immune traits of clams and oysters. These findings indicate that low levels of Cu contamination may enhance immunity of estuarine bivalves while moderate hypercapnia (such as predicted by the near future scenarios of the global climate change) does not strongly affect their immune parameters.

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Section: Interactive Effects Of Cu and P Co2 On Metabolism And Immunementioning

confidence: 99%

Interactive effects of copper exposure and environmental hypercapnia on immune functions of marine bivalves Crassostrea virginica and Mercenaria mercenaria

Ivanina

Hawkins

Sokolova

2016

Fish & Shellfish Immunology

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“…Металотіонеїни мають і виз начені антиоксидантні властивості [134]. Вони ві діграють також певну роль у підтриманні нормаль ного іонного балансу в клітині [139].…”

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Heavy metals genetic activity in eukaryotic cells

Macewicz

Лукаш

2001

Biopolym. Cell

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В огляді розглянуто різні аспекти пошкоджуючої дії деяких важких металів (нікель, хром (III), неорганічна ртуть та свинець). Особливу увагу приділено питанням, пов'язаним з мутагенною активністю зазначених металів (мутагенність їхніх іонів у різних тест-системах, механізми пошкодження генетичного матеріалу, механізми захисту клітини від мутагенного впливу важких металів), проте коротко також проаналізовано їхню токсичну дію, біохімічну активність, екологічні аспекти.

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Effects of Short‐Term Methylmercury Exposure on Metallothionein mRNA Levels in the Testis and Epididymis of the Rat

DUFRESNE,

CYR

1999

Journal of Andrology

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Methylmercury (MeHg) is a widespread environmental contaminant that causes reproductive dysfunction in men. Metallothioneins (MTs) are low‐molecular‐weight proteins that can bind heavy metals and protect the cell from metal toxicity. MT levels are increased by exposure to metals and physiological stressors. Although MTs have been identified in the testis and epididymis, little is known about their distribution and regulation in the epididymis or the effects of MeHg on MT levels in male reproductive tissues. The objective of this study was to determine whether MT I, II, and III mRNA are present in the epididymis, if their relative levels differ between epididymal segments, and if MeHg alters cellular mRNA levels for MT I, II, and III in the testis and epididymal segments of the rat. Northern blot analysis was done on total cellular RNA isolated from each of the four epididymal segments (initial segment [IS], caput [CT], corpus [CS], and cauda [CA] epididymidis) using a cDNA probe for MT I and MT II. MT I transcripts were present in all epididymal segments. The lowest mRNA levels were observed in the IS; these levels were 4‐fold less than in the CT and CS and 5.5‐fold less than in the CA. MT II mRNA levels were similar in the IS and CT but were eightfold higher in the CS and CA. A cDNA probe for MT III was generated by reverse transcription‐polymerase chain reaction using testicular RNA. MT III mRNA was detected only in the IS and CT and not in the CS and CA. To assess whether exposure to MeHg alters MT mRNA levels, rats were exposed for 14 days to one of five MeHg doses (0, 25, 50, 100, and 200 [μg/kg/day] via asubdermal osmotic pump. No changes were observed in either body weight or in the weights of the testis, epididymis, seminal vesicles, or ventral prostate between MeHg‐treated and control rats. Serum testosterone levels were significantly decreased only at the highest MeHg dose. In the testis, MeHg treatment resulted in 2.5‐ to 7‐fold increases in MT I mRNA levels. There were no changes in either MT II or MT III mRNA levels. In the initial segment of the epididymis, MT I mRNA levels were significantly increased only at the 50 μg/kg/ day dose, whereas there were no significant differences in MT II mRNA levels. In the caput epididymis, MT I mRNA levels were significantly lower at the 50 and 100 μg/kg/day dose. MT II mRNA levels were also lower, with the exception of the 50 μg/kg/day dose. Although MT III mRNA levels were lower at the two lower doses, levels were not different from controls in the two highest doses tested. In the corpus epididymidis, MeHg did not alter MT I mRNA levels, and MT II was higher only in the 50 μg/kg/day group. In the cauda epididymidis, MT I mRNA levels were decreased in a dose‐dependent manner by up to 63%. MT II levels were unaltered. Together these data indicate that exposure of adult rats to MeHg can modulate MT mRNA levels in both the testis and epididymal segments. Furthermore, changes in MT mRNA levels following exposure to MeHg differ between epididymal segments, suggesting either differences in MeHg accumulation or differences in MT modulation.

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Protective effect of metallothionein on intracellular pH changes induced by cadmium

Cited by 13 publications

References 28 publications

Interactive effects of copper exposure and environmental hypercapnia on immune functions of marine bivalves Crassostrea virginica and Mercenaria mercenaria

Interactive effects of copper exposure and environmental hypercapnia on immune functions of marine bivalves Crassostrea virginica and Mercenaria mercenaria

Heavy metals genetic activity in eukaryotic cells

Effects of Short‐Term Methylmercury Exposure on Metallothionein mRNA Levels in the Testis and Epididymis of the Rat

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