The state of internal organs in tugun larvae was analyzed histologically in the intact (control) group, the group treated with a water-soluble oil fraction (WSOF) in fivefold excess over the maximum allowable concentration, and the group exposed in a weak pulsed magnetic field at the stage of hatching, prior to treatment with WSOF. Larvae of the second group had severe pathologies of inner organs that caused 100% mortality before the age of 15 days, but no pathomorphological changes in the organs of larvae and juvenile fish of the third group were revealed for up to 40 days. Probable causes of high resistance to the toxic agent in fish of the experimental group are discussed. 相似文献
During acute oral intoxication by cadmium compounds, gastrointestinal epithelial damage contributes to immediate toxicity. However, secondary systemic toxicity may develop due to intestinal uptake of cadmium. This review presents an evaluation of the effects of chelators on the acute toxicity of cadmium after parenteral or oral exposure and on the intestinal uptake of cadmium. This review shows:
Chelating agents may affect the acute toxicity of cadmium in a variety of ways depending on the exposure route for cadmium and administration route for the chelator.
With regard to survival, systemic toxicity of absorbed cadmium is of major importance, as intraperitoneal administration of chelators could eliminate or reduce mortality due to orally administered cadmium chloride.
Lipophilicity of chelators and their cadmium complexes may result in extensively augmented intestinal uptake. However, hydrophilic chelators may efficiently reduce the intestinal cadmium uptake.
For hydrophilic chelators, the stability of the cadmium complex is an important determining factor of efficacy.
The optimal oral antidote towards orally administered cadmium are the BAL analogs, especially DMSA, while the optimal intraperitoneal antidotes towards orally or intraperitoneally administered cadmium are the higher members of the polyaminopolycarboxylate family, especially TTHA.
When administered simultaneously (DMSA orally and TTHA intraperitoneally), these chelators synergistically reduce the whole‐body retention of cadmium.
In conclusion, chelation treatment in acute oral cadmium intoxication should first prevent/reduce intestinal damage and uptake by rapid oral administration of a chelating antidote and then alleviate systemic toxicity due to absorbed cadmium and enhance renal/biliary cadmium excretion by parenteral administration of a chelating antidote. 相似文献
Daphnia magna, a freshwater microcrustacean, is currently tested as an alternative experimental species in research dealing with nerve agents poisonings treatment. Because of this, the toxicity of the nerve agent tabun (a cyanide-group containing organophosphate) to Daphnia had to be examined by estimating the EC50 values. The immobilization of daphnids was chosen as the end-point. It was found that D. magna is sensitive to small amounts of tabun, even after 15 min exposure, and tabun toxicity increases with time. The estimated EC50 values for 15, 30, 45, and 60 min exposure were as follows: 67.39, 38.10, 26.95, and 21.9 μg l?1. In addition, the toxicity of media to which tabun was added 24 h before the start of experiments was examined. The results obtained indicate that daphnids can be used in experiments with nerve-agent intoxication treatment. 相似文献