RESUMO
The accumulation of ten metals in turpentine-induced abscesses of different ages has been studied in rats. The maximum metal concentration ratio between the abscesses and the non-inflamed contralateral muscle was greater than 1 for all the metals studied, the lowest being 2.5 for Zn, and the highest 36 for Th. The ratio remains greater than 1 for more than 28 days for all metals except Ga. There is a marked increase of beta-glucuronidase activity in the inflamed tissue which correlates well with the metal concentration. In contrast the acid phosphatase activity was reduced for the first few days after turpentine injection and never rose above the normal muscle activity. The metals showing the highest uptake in the inflamed lesion appear to be those which are transported in the blood as a transferrin complex.
Assuntos
Abscesso/metabolismo , Metais/metabolismo , Abscesso/enzimologia , Fosfatase Ácida/metabolismo , Animais , Glucuronidase/metabolismo , Masculino , Músculos/metabolismo , Radioisótopos/análise , RatosRESUMO
The binding of Pu to liver cell membranes was studied and compared with that of iron with which plutonium shares some physiological properties. The binding of both metals is sensitive to pH changes and they can be dissociated from their binding sites by chelating agents and transferrin. The metal-binding proteins can be extracted with detergents. Both metals have at least two binding sites, the molecular weights of which lie between 150 and 400 kDa; the isoelectric points for iron are 5.5 and 6.5, and for plutonium 6.0 and 6.5. The significance of these results for plutonium uptake into liver cells is discussed.
Assuntos
Fígado/metabolismo , Nitratos , Plutônio/metabolismo , Animais , Membrana Celular/metabolismo , Cloretos , Compostos Férricos/metabolismo , Radioisótopos de Ferro , Cinética , Proteínas de Membrana/isolamento & purificação , Proteínas de Membrana/metabolismo , Ligação Proteica , Ratos , Transferrina/metabolismoRESUMO
Exposure of Co631 cells to 239Pu-citrate leads to continuous irradiation and results in increasing cell death which depends on dose and incubation time of the metal. The D37 is calculated to be 0.13 Gy. Plutonium-239 induces the amplification of the integrated SV40 sequences of the Co631 cells. Other cellular genes such as the alpha-actin gene were not amplified, indicating that the SV40-gene amplification is a selective process. Southern blot analysis of genomic DNA shows that not all S40 sequences are equally amplified. Excised sequences of the SV40 genome only appear after an exposure time of 4 days.