Subject(s)
Intestinal Obstruction/pathology , Leiomyoma/pathology , Torsion Abnormality/pathology , Uterine Neoplasms/pathology , Adult , Female , Humans , Intestinal Obstruction/etiology , Intestinal Obstruction/surgery , Leiomyoma/complications , Leiomyoma/surgery , Torsion Abnormality/etiology , Torsion Abnormality/surgery , Tumor Burden , Uterine Neoplasms/complications , Uterine Neoplasms/surgeryABSTRACT
We have applied the micronucleus (MN) assay to the measurement of genotoxicity in microcrustaceans. Daphnids (Daphnia magna) and Copepods (Acanthocyclops robustus) were collected in situ and acclimated in the lab for 24h. The MN assay was successful with the Daphnids but not with the Copepods. Adult Daphnids were exposed to sublethal concentrations of metals (Cu, Zn, Cd) or insecticide (deltamethrin) for 2 and 7d. Dose-dependent induction of MN was observed after 2 d exposure, with 2-fold induction at the highest doses for each chemical tested. The advantages and ecological relevance of using Daphnids in genotoxicity assessment are highlighted. The Daphnid assay may be a reliable test for aquatic genotoxicity hazard/risk assessment and a useful alternative to studies of amphibians.
Subject(s)
Daphnia/metabolism , Micronucleus Tests , Mutagenicity Tests/methods , Animals , Cadmium/toxicity , Copper/toxicity , Daphnia/drug effects , Nitriles/toxicity , Pyrethrins/toxicity , Zinc/toxicity , Zooplankton/drug effects , Zooplankton/metabolismABSTRACT
The literature on metallothioneins (MT) and metallothionein-like proteins (MTLP) in aquatic invertebrates is large and increasing, and yet inconsistencies and confusion remain, not least over the physiological role of MT and their use as biomarkers in environmental monitoring programmes. We have collated published information on MT in three important groups of aquatic invertebrates-the molluscs, crustaceans and annelid worms, and attempted to seek explanations for some of the apparent inconsistencies present in the dataset. MTs can be induced by the essential metals Cu and Zn and the non-essential metals Cd, Ag and Hg in both vertebrates and invertebrates, but their induction is variable. Such variation is intraspecific and interspecific, and is down to a variety of reasons environmental and physiological explored here. Against this background of variability MTs do appear to play roles both in the routine metabolic handling of essential Cu and Zn, but also in the detoxification of excess amounts intracellularly of these metals and of non-essential Cd, Ag and Hg. Different isoforms of MT probably play different physiological roles, and the dependence on MT in detoxification processes varies environmentally and between zoological groups. MTs can be used as biomarkers if used wisely in well-designed environmental monitoring programmes.
Subject(s)
Biomarkers , Environmental Exposure , Invertebrates/metabolism , Metallothionein/physiology , Metals/toxicity , Animal Structures/chemistry , Animals , Environmental Monitoring/methods , Invertebrates/chemistry , Metallothionein/genetics , Metallothionein/metabolism , Metals/analysis , Species Specificity , Time FactorsABSTRACT
Because of their wide geographic distribution, position in the trophic chain, rapid turnover, huge biomass and role in ocean biogeochemical cycles, copepods are regarded as important marine test species. Tigriopus brevicornis Müller, 1776 is a shallow water benthic marine species (Crustacea, Copepoda Harpacticoida). The toxicity of essential and non-essential metals (Ag, Cd, Cu, Hg, Ni and Zn) to Tigriopus brevicornis was determined by 96-h LC(50) testing. Comparative crustacean 96-h LC(50) data in the literature show that Tigriopus brevicornis is a sensitive species suggesting that copepods are good indicators of minimal lethal concentrations of metals. Groups of 1000 to 1500 adult copepods were exposed for 1 to 14 days to metals at concentrations in water, 3 for each metal, considered realistic in comparison with those encountered in polluted environments and far below lethal concentrations, in order to avoid protein metabolism disturbance. The response of Tigriopus brevicornis in terms of MT induction has been examined in specimens exposed to metals. The induction of these proteins and their implication in detoxificatory mechanisms and trophic transfer are discussed.
