Hepatotoxic effect of metallic pollutants on enzyme histochemical activities of yellow-legged gull Larus cachinnans michahellis liver.

We studied the hepatotoxic effect of heavy metals (cadmium, mercury, copper) on Mg2+ -ATPase, NADH diaphorase, succinic dehydrogenase and acid phosphatase of yellow-legged gull liver, using enzyme histochemical methods. The lysosomal enzyme activity of acid phosphatase was increased in all cases. However, the other enzyme activities appeared to be insensitive to the different metallic pollutants and to their respective levels, in contrast with literature experimental data showing plasma membrane and mitochondrial alterations. This controversy could be explained by the differences in dietary conditions and metal overloads. The molecular basis of the toxicities of metallic pollutants is discussed.

Neutron activation study of the natural elementary composition of edible sea urchins (Paracentrotus lividus Lamarck) in the National Park of Port-Cros (Mediterranean, France).

Neutron activation study of elementary composition was performed on edible sea urchins Paracentrotus lividus from the National Park of Port-Cros. The analysis allows the identification and quantification of 22 elements: antimony, arsenic, baryum, bromine, cerium, chromium, cesium, cobalt, gold, iron, lanthane, potassium, sodium, rubidium, samarium, scandium, selenium, silver, strontium, thorium, uranium and zinc. The concentration levels were higher in the soft organic parts (alimentary canals and gonads) for all the elements, except for strontium, which developed a strong affinity with calcareous hard parts (tests, spines, masticating apparatus). We also found high rates of baryum, arsenic, zinc, bromine and iron. The hypothesis on the origin of these elements is discussed. The data obtained on this referential zone will soon be used to appreciate the perturbation of the elementary composition of urchins by pollution in various parts of the French seashore.

Neutron activation study of the elementary composition of edible sea urchins (Paracentrotus lividus Lamarck) in marine creek area polluted by city sewages of Marseille (France).

Neutron activation study of elementary composition (Ag, As, Au, Ba, Br, Ce, Co, Cr, Cs, Fe, K, La, Na, Rb, Sb, Sc, Se, Sm, Sr, Th, U and Zn) was performed on edible sea urchins (Paracentrotus lividus Lamarck) from marine creek area polluted by city sewages from Marseille (France) after a purifying plant was brought into operation. Concentration levels were higher in soft organic parts (alimentary canals and gonads) for all the elements except for Sr which showed a strong affinity for calcareous parts (tests, spines and masticating apparatus). Certain elements present in the soft organic parts are rarely found in the hard parts. More than half the elements studied show higher concentrations in Marseille samples than in the referential region of Port-Cros National Park (France). That must be due to sewage rejection for a large number of them. This hypothesis is confirmed with regard to elements the values of which decrease significantly with the distance from the sewage emission point, e.g. Cr, Fe and Zn, and a little less for Ag, Ba, Ce, Rb, Sb, Sc, Se, Sm and Th. These results raise a question: has that artificial change on the elementary composition any toxicological effects on the urchin populations? This question is discussed.

Microscopic localization of mercury-selenium interaction products in liver, kidney, lung and brain of Mediterranean striped dolphins (Stenella Coeruleoalba) by silver enhancement kit.

Microscopic observation, using physical development of silver, was carried out to localize the mercury-selenium interaction products in the organs of Mediterranean striped dolphins. The silver-metal reaction products were located mainly in hepatocytes and macrophages for liver, in proximal tubules for kidney. They were less abundant in lung than in liver and kidney. The result of semi-quantitative histochemistry tests showed that silver staining deposits were more abundant at relatively high metal concentrations than low metal contents, but independent of the metal contents. Comparisons with the most concentrated metal contents suggested that there might be a new complex of mercury and selenium, which could not be stainable by physical silver development.

Mercury, zinc and selenium bioaccumulation in tissues and organs of Mediterranean striped dolphins Stenella coeruleoalba meyen. Toxicological result of their interaction.

Neutron activation analysis of 13 Mediterranean striped dolphins Stenella coeruleoalba showed high mercury and selenium contaminations of main tissues and organs of these cetaceans. The mercuric contents were excessive, particularly in liver (from 68 to 2272 micrograms/g dry wt. basis), then in kidney, lung, muscle, heart and brain. The selenium concentrations were also high in liver (from 45 to 1320 micrograms/g dry wt. basis), then in kidney, lung, muscle, skin and heart. The main way of contamination seems to be the food through trophic network, but skin and lung are also able to play a part which must be elucidated. The average Hg/Se ratios in liver and kidney were respectively 1.82 and 1.59. Linear relationship between mercury and selenium concentrations in tissues and organs, particularly in liver and kidney, were confirmed. The mercury and selenium interaction on a toxicological point of view was established by a statistical approach; in the same way, intervention of zinc, metallothioneins and glutathiones have been discussed.

[The benthic red alga Ceramium ciliatum var. robustum (J.Ag.) G. Mazoyer is a remarkable biological indicator of littoral mercury pollution]. / L'Algue rouge benthique Ceramium ciliatum var. robustum (J. Ag.) G. Mazoyer est un remarquable indicateur biologique de la pollution mercurielle littorale

The study of mercury composition of red Algae Ceranium ciliatum var. robustum, comparatively with other marine organisms and considering its growth and the extent of pollution at various harvesting points: reveals that this seaweed constitutes a conspicuous biological indicator for the littoral mercury pollution.