Sub-Chronic Oral Exposure to Iridium (III) Chloride Hydrate in Female Wistar Rats: Distribution and Excretion of the Metal

Abstract

Iridium tissue distribution and excretion in female Wistar rats following oral exposure to iridium (III) chloride hydrate in drinking water (from 1 to 1000 ng/ml) in a sub-chronic oral study were determined. Samples of urine, feces, blood and organs (kidneys, liver, lung, spleen and brain) were collected at the end of exposure. The most prominent fractions of iridium were retained in kidney and spleen; smaller amounts were found in lungs, liver and brain. Iridium brain levels were lower than those observed in other tissues but this finding can support the hypothesis of iridium capability to cross the blood brain barrier. The iridium kidney levels rose significantly with the administered dose. At the highest dose, important amounts of the metal were found in serum, urine and feces. Iridium was predominantly excreted via feces with a significant linear correlation with the ingested dose, which is likely due to low intestinal absorption of the metal. However, at the higher doses iridium was also eliminated through urine. These findings may be useful to help in the understanding of the adverse health effects, particularly on the immune system, of iridium dispersed in the environment as well as in identifying appropriate biological indices of iridium exposure.

Novel iridium (III)‑derived organometallic compound for the inhibition of human platelet activation

“…The ESR spectrometry results from the present study provide direct evidence that Ir-3 does not significantly reduce OH· formation in collagen-stimulated platelet suspensions and Fenton reaction solution. In addition, Ir tissue distribution and excretion in rats following sub-chronic oral administration of Ir (III) chloride hydrate (1–1,000 ng/ml) for 90 days was previously determined ( 31 ). Concerning the distribution, the majority of Ir was located in the kidney and spleen, and smaller amounts were observed in the lungs, liver and brain.…”

“…Furthermore, the dose-dependent increase of Ir levels in the serum demonstrated that the Ir was distributed in the blood compartment. For excretion, the body clearance of Ir primarily took place by elimination via feces, and this was also dose-associated ( 31 ).…”