Translocation of subcutaneously injected chrysotile fibres: Potential cocarcinogenic effect on lung cancer induced in rats by inhalation of radon and its daughters
Monchaux, G; Chameaud, J; Morlier, JP; Janson, X; Morin, M; Bignon, J
HERO ID
3085261
Reference Type
Book/Book Chapter
Year
1989
Language
English
PMID
| HERO ID | 3085261 |
|---|---|
| Year | 1989 |
| Title | Translocation of subcutaneously injected chrysotile fibres: Potential cocarcinogenic effect on lung cancer induced in rats by inhalation of radon and its daughters |
| Book Title | Non-occupational exposure to mineral fibres |
| Authors | Monchaux, G; Chameaud, J; Morlier, JP; Janson, X; Morin, M; Bignon, J |
| Editor | Bignon, J; Peto, J; Saracci, R |
| Publisher Text | International Agency for Research on Cancer |
| City | Lyon, France |
| Page Numbers | 161-166 |
| Abstract | Exposure to radon 222 and its daughters has been shown to induce lung cancer in rats. The cocarcinogenic effect of intrapleurally injected mineral fibres in rats which have previously inhaled radon has also been established. The aim of this work was to establish whether a similar process could be induced at a distance from the lungs by subcutaneous injection of chrysotile fibres. Three groups of animals were used: (1) 109 rats which inhaled radon only (dose: 1600 working-level months (WLM]; (2) 109 rats given a subcutaneous injection in the sacrococcygeal region of 20 mg of chrysotile fibres after inhalation of the same dose of radon; and (3) 105 rats injected with fibres only. No mesotheliomas occurred in any of the 3 groups. The incidence of lung cancer was 55% in group 2, 49% in group 1 and 1% in group 3. Statistical analysis using Pike's model showed that the carcinogenic insult was slightly higher in group 2 than in group 1. Electron microscopy analysis of fibre translocation from the injection site showed that less than 1% of injected fibres migrated to the regional lymph-nodes and only about 0.01% to the lungs. After injection, the mean length of the fibres recovered in lung parenchyma increased with time, suggesting that short fibres are cleared by pulmonary macrophages whereas long fibres are trapped in the alveolar walls. Although the high tumour incidence observed in group 1 might have masked the cocarcinogenic effect induced by the fibres, it is possible that this effect can occur only at short distances. The translocation of long, thin fibres to the lung and the chronic inflammatory reaction are considered as possible promoters of pulmonary carcinogenesis. |
| Pmid | 2545604 |
| Wosid | MEDLINE:2545604 |
| Is Certified Translation | No |
| Dupe Override | No |
| Series | IARC Scientific Publications, no. 90 |
| Isbn | 9789283211907 |
| Is Public | Yes |
| Language Text | English |
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