Abstract: | Abstract The biochemical and histopathological changes in lungs of guinea pigs were studied 120 days after intratracheal injection of three varieties of asbestos dusts, viz. chrysotile, amosite and anthophyllite. The salient histopathological features observed were the development of dust cell lesions in the lungs of animals exposed to the different varieties of asbestos. Maximum fibrosis and minimal asbestos body formation was observed in animals exposed to chrysotile and anthophyllite, respectively. With amosite and anthophyllite the development of diffuse interstitial fibrosis ensued, accompanied by well developed asbestos body formation in the amosite exposed animals. Biochemical studies revealed significant alterations in various phosphorylated compounds, an accumulation of orthophosphate and depletion of esters and nucleotides being very marked. RNA content increased significantly in the amosite treated group while the nucleic acid content remained unaltered in the chrysotile group. |