[The fibrogenic effect of artificial ceramic fibres in experimental rats]

The fibrogenic effect of aluminosilicate ceramic fibres in rats administered intratracheally with a single dose of 25 mg was assessed on the basis of the lung hydroxyproline concentration and morphological changes in the lung parenchyma and mediastinum lymphatic nodes. Control groups were composed of rats administered with NaCl saline and crocidolite UICC. The rats were exposed for 6 and 9 months. It was found that after 6 and 9 months, aluminosilicate ceramic fibres (L-1, Langfaser, Thermowool and Kaowool) showed weak fibrogenic properties. The range of changes in reactivity, and the presence of fibres of fibrous connective tissue in granulomas, induced by ceramic fibres were lower than the range of changes and the contribution of connective tissue produced by asbestos and crocidolite UICC.