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Toxicological information

Immunotoxicity

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Analysis of the expression of the proliferating cell nuclear antigen (PCNA) was used to determine the presumed hyperplastic character of morphological changes in the rat thyroid evoked by bromide administration. Male rats were fed by a diet containing additional bromide for 16, 66 or 133 days. The thyroids of treated animals showed activation of growth of the follicular component as well as diffuse and focal microfollicular rearrangement of the parenchyma with higher follicular cells accompanied by a decrease of the amount of colloid even at low bromine concentrations (10-100 mg Br-/L drinking water). The PCNA-LI index was significantly higher in bromide exposed animals and correlated well with the histological changes, with bromide concentration and with an increased mitotic activity of the follicular cells.

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Additional information

Sodium bromide is an inorganic salt that dissociates to its composite ions in aqueous solutions at environmental pH and temperature. Comparison of the available data on the various bromide salts have shown that the bromide ion is the relevant ion for determination of the toxicological profile with simple cations such as potassium, sodium or ammonium, that are ubiquitous in nature, having little or no influence on the bromide ion properties. It is therefore justified to read-across data from other inorganic bromide salts to sodium bromide.

Analysis of the expression of the proliferating cell nuclear antigen (PCNA) was used to determine the presumed hyperplastic character of morphological changes in the rat thyroid evoked by bromide administration. Male rats were fed by a diet containing additional bromide for 16, 66 or 133 days. The thyroids of treated animals showed activation of growth of the follicular component as well as diffuse and focal microfollicular rearrangement of the parenchyma with higher follicular cells accompanied by a decrease of the amount of colloid even at low bromine concentrations (10-100 mg Br-/L drinking water). The PCNA-LI index was significantly higher in bromide exposed animals and correlated well with the histological changes, with bromide concentration and with an increased mitotic activity of the follicular cells.

Justification for classification or non-classification