Abstracts / Marine Environmental Research 50 (2000) 61±81
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Abstract The chlorophyte macroalgae, Enteromorpha compressa, is found in freshwater as well as marine environments. The freshwater form is present only for a short time, from late May to July, whereas the marine form is present along the coast throughout the year. In this study we compared the detoxication capacity of this algae from both ecosystems to investigate why the freshwater form shows such a shortened lifespan. We measured the activity of the guajacol peroxidase and of the microsomal and soluble glutathione S-transferase, two enzymes representing the Phase I (peroxidase) and Phase II (microsomal and soluble glutathione S-transferase) detoxication systems. Furthermore, we investigated the activity of glutathione reductase, an enzyme related to maintenance of the glutathione pool. We found that the marine form of E. compressa has lower enzyme activities compared with the limnic algae, whereas the substrate speci®city of both forms seems to be equal. PII: S0141-1136(00)00251-8
Metabolism of the S-triazine herbizide atrazine in early life stages of the zebra®sh, Danio rerio C. Wiegand a, E. Krause b, C. Steinberg a, S. P¯ugmacher a a
Institute of Freshwater Ecology and Inland Fisheries, MuÈggelseedamm 301, D-12587 Berlin, Germany b Institute of Molecular Pharmaclogy, Alfred-Kowalke Str. 4, D-10315 Berlin, Germany
Abstract Increasing anthropogenic pollution of the environment can have adverse consequences for organisms which are more subtle than direct toxicity. Detectable levels of persistent pollutants remain even if the substance is no longer used. An example is atrazine, a herbicide in common use throughout the world but one which has been banned in Germany since 1992. As a lipophilic substance, atrazine is bioconcentrated which may lead to chronic intoxication or physiological stress. In order to withstand chemical stressors, many organisms possess detoxication enzymes, for example certain P-450 monoxygenases and glutathione S-transferases. But detoxication demands cellular energy, and in developing organisms, such as ®sh embryos which have particularly high energy needs for sustaining growth and organogenesis, the additional energy needs of detoxication may present additional stress. In this study, uptake of atrazine, cytochrome P-450 binding spectra, eects on microsomal and soluble glutathione Stransferase activities, and the initial detoxication steps of atrazine via microsomal and soluble glutathione S-transferases were studied using early life stages of zebra®sh. PII: S0141-1136(00)00152-5