English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

Copper (Cu2+) intoxication has been shown to induce pathological changes in various tissues. The mechanism underlying Cu2+ toxicity is still unclear. It has been suggested that the Na+/K(+)-ATPase and/or a change of the membrane permeability may be involved. In this study we examined the effects of Cu2+ on the Na+ and Ca2+ homeostasis of cultured human skeletal muscle cells using the ion-selective fluorescent probes Na(+)-binding benzofuran isophatalate (SBFI) and Fura-2, respectively. In addition, we measured the effect of Cu2+ on the Na+/K(+)-ATPase activity. Cu2+ and ouabain increase the cytoplasmic free Na+ concentration ([Na+]i). Subsequent addition of Cu2+ after ouabain does not affect the rate of [Na+]i increase. Cu2+ inhibits the Na+/K(+)-ATPase activity with an IC50 of 51 microM. The cytoplasmic free Ca2+ concentration ([Ca2+]i) remains unaffected for more than 10 min after the administration of Cu2+. Thereafter, [Ca2+]i increases as a result of the Na+/Ca(2+)-exchanger operating in the reversed mode. The effects of Cu2+ on the Na+ homeostasis are reversed by the reducing and chelating agent dithiothreitol and the heavy metal chelator N,N,N',N'-tetrakis (2-pyridylmethyl)ethylenediamine (TPEN). In conclusion, SBFI is a good tool to examine Na+ homeostasis in cultured human skeletal muscle cells. Under the experimental conditions used, Cu2+ does not modify the general membrane permeability, but inhibits the Na+/K(+)-pump leading to an increase of [Na+]i. As a consequence the operation mode of the Na+/Ca(2+)-exchanger reverses and [Ca2+]i rises.

Copper toxicity in cultured human skeletal muscle cells: the involvement of Na+/K+-ATPase and the Na+/Ca2+-exchanger