Interplay of calcium and cadmium in mediating cadmium toxicity.

This study was conducted to determine if the cadmium-mediated inhibition of vitellogenesis observed in fish collected from contaminated areas or undergoing experimental exposure to cadmium correlated with modification in the transcriptional activity of the estrogen receptor. A recombinant yeast system expressing rainbow trout (Oncorhynchus mykiss) estradiol receptor or human estradiol receptor was used to evaluate the direct effect of cadmium exposure on estradiol receptor transcriptional activity. In recombinant yeast, cadmium reduced the estradiol-stimulated transcription of an estrogen-responsive reporter gene. In vitro-binding assays indicated that cadmium did not affect ligand binding to the receptor. Yeast one- and two-hybrid assays showed that estradiol-induced conformational changes and receptor dimerization were not affected by cadmium; conversely, DNA binding of the estradiol receptor to its cognate element was dramatically reduced in gel retardation assay. This study provides mechanistic data supporting the idea that cadmium is an important endocrine disrupter through a direct effect on estradiol receptor transcriptional activity and may affect a number of estrogen signaling pathways.

https://bioone.org/journals/biology-of-reproduction/volume-63/issue-1/biolreprod63.1.259/Inhibition-of-Rainbow-Trout-Oncorhynchus-mykiss-Estrogen-Receptor-Activity-by/10.1095/biolreprod63.1.259.pdf

Inhibition of Rainbow Trout (Oncorhynchus mykiss) Estrogen Receptor Activity by Cadmium

Calcium-Mediated Activation of c-Jun NH2-Terminal Kinase (JNK) and Apoptosis in Response to Cadmium in Murine Macrophages

Increase of striatal dopamine release by cadmium in nursing rats and its prevention by dexamethasone-induced metallothionein

The data reported show that heavy metals, such as Hg2+, Cu2+, Cd2+, and Zn2+, are able to affect the mechanisms of Ca2+ homeostasis. It has been demonstrated that heavy metals, probably interacting with the sulphydrylic groups of the membrane proteins involved in the structure of the Ca2+ channels, can enhance the flux of Ca cations through the plasma membrane, the membrane of calciosomes, and mitochondria.

Rolf Gall

Papers

Calcium/calmodulin-dependent phosphorylation and the effect of cadmium in cultured fish cells.