[Biological evaluation of experiments in rats of Australian and Italian talc aggressiveness].

In order to evaluate biological effects of Austrian and Italian talc, pulmonary and hemolytic tests as well as pathomorphological examinations were performed. 120 Wistar rats divided into 5 groups were given intratracheally 50 mg of the examined talc dust suspended in 0.5 ml of 0.9 NaCl. The control group received one 0.5 ml dose of NaCl. The observation periods were 6 and 9 months. Then the biochemical tests for hydroxyproline content in the lung were carried out along with patho-morphologic tests to evaluate the fibrogenic activity of the talcs examined. In animals the intratracheal insufflation of talc dust causes inflammatory changes within the bronchi and lungs. On the basis of biochemical examination of lung homogenates, the differences in the hydroxyproline content were determined. After 6 months the symptoms of chronic inflammation and cellular modules developed. Within another 3 months the symptoms of chronic atrophic inflammation in the bronchi were observed and cellular modules containing dust particles were detected in the lung. Hemolytic test revealed a slightly higher degree of aggressiveness of the Austrian talc.