Effect of thimerosal and other sulfhydryl reagents on calcium permeability in thymus lymphocytes.
We have studied the effects of thimerosal, a mercurial compound extensively used as a preservative, as well as other sulfhydryl reagents (e.g. p-hydroxymercurybenzoate, hydrogen peroxide, bromophenacyl bromide, and mercuric chloride) on Ca2+ homeostasis and the redox status of sulfhydryl groups in thymus lymphocytes. They all induced an increase in [Ca2+]i which was blocked with dithiothreitol, suggesting that they act via the oxidation or blockade of sulfhydryl groups. [Ca2+]i increase could be directly related to the effect of the different reagents on cellular protein sulfhydryl content. Experiments with ethidium bromide indicate that the observed rise in [Ca2+]i was not due to a non-specific increase in membrane permeability. Thimerosal differs from the other agents studied in its oxidative properties, which is probably linked to the production of a potent reductor molecule, thiosalicylic acid, which may modulate its oxidative capacity.
Departamento de Bioquímica Médica y Biología Molecular, Facultad de Medicina, Universidad de Sevilla, Spain.
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D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002463:Cell Membrane Permeability / Q000187:drug effects; D002470:Cell Survival; D005260:Female; D008297:Male; D010084:Oxidation-Reduction; D051381:Rats; D017208:Rats, Wistar; D013439:Sulfhydryl Reagents / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000187:drug effects* / Q000378:metabolism; D013849:Thimerosal / Q000494:pharmacology*; D013950:Thymus Gland / Q000166:cytology
D013439:Sulfhydryl Reagents; D013849:Thimerosal; D002118:Calcium