Combined Metal Treatment Research Articles

Metal induced changes in the erythrocyte membrane of rats

Lead, zinc and copper were administered i.p singly or in combination as acetate salts to rats for 14 consecutive days. It was observed that lead induced drastic changes, copper induced moderate changes but zinc did not cause any significant change in the cholesterol and phospholipid content, hexose, hexosamine and sialic acid levels and activities of the erythrocyte membrane enzymes — acetylcholinesterase (AChE), NADH dehydrogenase and Na +-K + ATPase. In the combined metal treatment the presence of zinc considerably reduced the changes induced by lead and copper.

Chromium and cadmium bioaccumulation and toxicity inHydrilla verticillata(1.f.) Royle and Chara corallina wildenow∗

Abstract Bioaccumulation and toxicity of chromium and cadmium individually as well as in combinations were studied in aquatic macrophytes Hydrilla verticillata and Chara corallina. Both plants showed ability to accumulate these metals in individual as well as in combined treatments. Cadmium accumulation was more than Cr in both the plants at 1.0 μg cm‐3 of metals. The cadmium uptake in combined metal condition was enhanced and uptake of Cr being reduced. Individual metal phytotoxicity showed that Cd was more toxic than Cr, however, the combined toxicity of metals was more pronounced. Results showed that uptake of relatively more toxic metal Cd was enhanced in the presence of Cr concomitantly resulting in increased toxicity under combined metal treatments.

Uptake and toxicity op metals inscirpus lacustrisL. andbacopa monnieril.

Abstract Uptake and toxicity of copper and chromium were studied in single and combined metal treatments in the root and shoot of B. monnieri and S. lacustris. Results showed more uptake of metal in the root than in the shoot.In combined metal treatments, uptake of Cu was inhibited while that of Cr enhanced. Chromium ameliorated the Cu toxicity in combined metal treatments. Results indicated that these plants could be used in bio‐monitoring and abatement of metal pollution in closed water bodies.

Differential combined effect of cadmium and nickel on hepatic and renal glutathione S-transferases of the guinea pig.

When male guinea pigs were given a single dose of Cd (2.0 mg Cd2+/kg, ip) 72 hr prior to sacrifice, the hepatic reduced glutathione (GSH) level did not change although glutathione S-transferase (GST) activities toward the substrates 1-chloro-2,4-dinitrobenzene (CDNB), 1,2-dichloro-4-nitrobenzene (DCNB), ethacrynic acid (EAA), and 1,2-epoxy-3-(p-nitrophenoxy) propane (ENPP) increased significantly as compared to controls. Cd did not change the renal GSH level and GST activities toward CDNB and EAA. However, significant increase was observed in the GST activity for DCNB whereas GST activity for ENPP was significantly inhibited by Cd. When the animals were given a single dose of Ni (14.8 mg Ni2+/kg, sc) 16 hr prior to sacrifice, significant increases were observed in hepatic GSH level and GST activities toward CDNB, DCNB, EAA and ENPP. Ni, however, depressed the renal GSH level and GST activities toward CDNB, DCNB and ENPP significantly. The renal GST activity toward EAA remained unaltered. For the combined treatment, guinea pigs received the single dose of Ni 56 hr after the single dose of Cd and then they were killed 16 hr later. In these animals, no significant alteration was observed in the hepatic GSH level. The augmentation of elevation was observed in hepatic GST activities toward CDNB and DCNB. Combined metal treatment did not potentiate the elevation of hepatic GST activities toward EAA and ENPP to any greater degree. The depression of renal GSH level was significantly ameliorated by the combined treatment. Combination treatment potentiated the depression of renal GST activity for ENPP but not for CDNB.(ABSTRACT TRUNCATED AT 250 WORDS)

Chromium and manganese uptake byHydrilla verticillata(l.f.) royle : Amelioration of chromium toxicity by manganese!

Abstract Toxicity and uptake of chromium and manganese in Hydrilla verticillata were studied in individual and combined metal treatments. Plants showed substantial uptake of metals, however, it was more in case of manganese during individual metal treatments. In combined metal condition, chromium uptake was inhibited while manganese uptake was enhanced. Manganese ameliorated chromium toxicity by inhibiting its uptake in combined metal treatments.

The composition and morphology of yeast nuclear scaffolds

The yeast nuclear scaffold has been shown to bind with high affinity to genomic sequences that permit autonomous DNA replication of plasmids (ARS elements). We describe here conditions for the isolation of a histone-free nuclear substructure, the nuclear scaffold, from Saccharomyces cerevisiae. We examine the protein composition of this structure,and the conditions under which topoisomerase II, the nuclear factor RAP-1 and RNA polymerase II co-fractionate with the scaffold. We find that exposure of nuclei to a combined metal and heat treatment (0.5mM Cu(2) +, 37 degree centigrade prior to detergent extraction is required for effective stabilization of these proteins with the scaffold. Electron microscopy of the residual nuclei extracted with non-ionic detergents shows the absence of a typical peripheral lamina structure.