Limitations on the uptake of mercury vapour by human erythrocytes in a closed exposure system
✍ Scribed by Stefan Halbach
- Publisher
- John Wiley and Sons
- Year
- 1981
- Tongue
- English
- Weight
- 483 KB
- Volume
- 1
- Category
- Article
- ISSN
- 0260-437X
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✦ Synopsis
Previous in v i m studies using the exposure of suspensions of normal human erythrocytes to mercury vapour (Hgo) in Warburg vessels revealed a broad variation of the cellular Hg uptake in the presence of hydrogen peroxide and furnished evidence for an oxidation of Hgo by the catalase-H202 pathway. This report describes the uptake of Hgo in the same exposure system as it depends on haematocrit, H202 supplementation and exposure time. The results indicate that the uptake of vapour by the whole suspensions was virtually independent of haematocrit and of the H 2 0 2 supplementation at high rates of H202 infusion, whereas at low rates it was directly proportional to the amount of peroxide added. Since the retention of mercury by the medium is negligible, the haemoglobin-related (specific) uptake is inversely proportional to the haematocrit at high rates of H202 infusion. These results are consistent with the conclusion that the incorporation of Hgo by erythrocytes is controlled by two processes: transfer of vapour to the cells and enzymic oxidation. The net rate of uptake is limited by the oxidizing capacity at low, and by the vapour transfer at high H z 0 2 supplementation. As a practical consequence of these findings the spread of the specific uptakes reported in the literature is considerably reduced if the values observed when transfer becomes rate limiting are related to the haematocrit.