Morphological and biochemical evidence of the toxic effect of pentachlorophenol on the developing embryos of the sea urchin

356 Interactions of copper and manganese: A mechanism by which manganese alleviates copper toxicity to the marina diatom, Nitzschia closterium (Ehrenberg) H. S m i t h Stauber JL; Florence TH CSIRO Division of Energy Chemistry, Sutherland, NSH Z Z 3 Z , Austra lia AQUAT. T O X I C O L . ; 7 / ~ ( Z ~ l - Z 5 ~ ) / 1 9 8 5 / The mechanism by which manganese (~.Z a n d qZ mug H n . l s u p -sup 1) ameliorates the toxicity of copper 10-60 mug C u . l s u p -sup 1 ) to the marine diatom, Nitzschla closterium IEhrenberg) H. S m i t h , was investigated using unsupplemented sea water for growth rate experiments. Speciation of manganese associated with the cells, intracellular and extracellular manganese and copper concentrations, and competitive bin~ing between copper and manganese were studied using ultrafiltration, anodic stripping voltammerty and radiochemical techniques. Cells cultured before the sea-water assay and in the absence of manganese accumulated high intracellular copper, and their growth rate was more sensitive to copper than cells cultured in the presence of manganese. Manganese associated wi~h the cells was present as manganese ( I Z ) and/or 1111) h y d r o x i d e s , rather than as the fully oxidized HnOsub Z. It is proposed that manganese IIII) hydroxide, like iron IZII) hydroxide and cobal~ (III) hydroxide, adsorbs copper very effectively on the membran~ surface and prevents its penetration into ~he cell. Competitive interactions between manganese and copper occurred at the cell surface, but copper had no effect on lntracellular manganese. O n l y @ mug Hn.lsup -sup 1 was required to alleviate copper toxicity, compared t o 7 9 0 mug F e . l s u p -sup 1. In the presence of algae, copper ions had a greater affinxty for manganese in sea water than iron at similar concentrations, which may partially account for the relative effectiveness of manganese as a protective agent. In addition, manganese can scavenge the toxic superoxide radical (Osub Z[dot)sup -), catalyzing i~s dismutation to Hsub Z O s u b Z a n d O s u b Z. M a n g a n e s e was unable toxicity, nor did it inhibit the toxicity copper complexes, such as copper oxinate,

to reverse copper of lipid-soluble t o N. c l o s t e r i u m .

Morphological and biochemical evidence of the toxic effect of pentachlorophenol on the developing embryos of the sea urchin Ozretic B; Kra~novic-Ozretic M ' R u d j e r Boskovtc Institute', Center of Marine Research, 5ZZIO Roving, Yugoslavia AQUAT. T O X Z C O L . ; 7 / ~ l Z 5 5 - 2 6 3 ) / 1 9 8 5 / The effect of pentachlorophenol [POP) (0.1-0.8 mg.lsup -sup 1) on the activity of some basic enzymes {G6P-OH, GOT a n d G P T ) a n d on the production of echinochrome in sea urchin developing eggs (Paraoentrotus lividus Lam.) has been measured. The rate of development and the lethality of the developing embryos were also established. All the properties measured, except for the G6P-DH activity were negatively correlated t o t h e PCP concentration. The toxic effec~ of the compound was clearly manifested in disturbed morphogenesis and lowered survival.