[Experimental pneumoconiosis induced by cemented tungsten and sequential concentrations of cobalt and tungsten in the lungs of the rat (author's transl)].
Experimental pneumoconiosis was induced by intratracheal injection of dusts of presintered cemented tungsten carbide, G2 (WC : Co=98 : 2) and TX20 (WC : Co : TiC : TaC=64 : 16 : 6 : 14) into the lungs of rats in order to document the pathological changes in lung tissues associated with environmental cobalt and tungsten. The following results were obtained. 1) Six months after the administration of G2 and TX20 dusts, marked fibrotic foci were noted and tungsten was detected in the lung tissues of all of the experimental animals. 2) Twelve months after the administration of both dusts, both the fibrotic changes and the tungsten levels were reduced in both test groups, but the reduction was more notable in the G2 group. The cases with fibrotic changes were relatively concomitant with the cases in which tungsten was detected. 3) On examination of tissue levels of cobalt derived from the dust, the cobalt levels in the lungs and bone tissues were less influenced by the dust of the G2 group at any point of investigation, whereas only the pulmonary cobalt levels at six months after the administration of the TX20 group showed a remarkable influence from the dust cobalt (p less than 0.01). 4) In the cases where tungsten was detected six months after the administration of both groups and twelve months after the administration of the TX20 group, pulmonary cobalt levels had not reached the value that should have been gained by the addition of expected values (dust cobalt levels calculated from the tungsten levels) to the control values. 5) The above results indicate that both G2 and TX20 dusts induced marked fibrotic changes in rat pulmonary tissues. However, these changes were reversible to some extent. In addition, a portion of the dust cobalt was dissolved in the body fluid and disappeared from the pulmonary fields.
D000818:Animals; D003035:Cobalt / Q000032:analysis*; D008168:Lung / Q000032:analysis* / Q000473:pathology; D011009:Pneumoconiosis / Q000209:etiology / Q000473:pathology*; D051381:Rats; D013249:Sternum / Q000032:analysis; D014414:Tungsten / Q000032:analysis*; D017973:Tungsten Compounds
D017973:Tungsten Compounds; C002802:tungsten carbide; D003035:Cobalt; D014414:Tungsten