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Activation of calmodulin by the essential trace element chromium
Cell Calcium
|June 1, 1987
Summary
Chromium activates calmodulin, a key protein, at nanomolar concentrations found in welders. This may explain chromium toxicity symptoms, even without external signs.
Area of Science:
- Biochemistry
- Toxicology
- Environmental Health
Background:
- Chromium is an essential trace element at low concentrations but toxic at higher levels, causing issues like contact dermatitis.
- Chromium's ionic radius is similar to, yet distinct from, other metal cations known to activate calmodulin in vitro.
Purpose of the Study:
- To investigate the effect of chromium on calmodulin activation.
- To determine the concentration ranges at which chromium activates calmodulin.
- To explore the potential biological relevance of chromium-induced calmodulin activation in vivo.
Main Methods:
- In vitro experiments measuring calmodulin activation by chromium across different concentration ranges.
- Measurement of red blood cell chromium levels in stainless steel welders and healthy controls.
Main Results:
- Chromium activates calmodulin significantly at nanomolar concentrations (76% of maximum activation), with lesser activation in the micromolar range.
- Welders exposed to stainless steel showed red cell chromium levels of 28.2 ± 3.3 nM, significantly higher than controls (7.5 ± 0.7 nM).
Conclusions:
- Intracellular chromium concentrations, particularly in exposed individuals like welders, can reach levels sufficient to activate calmodulin in vitro.
- The inappropriate activation of calmodulin by chromium may play a role in chromium biology and contribute to toxicity symptoms.