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Toxicity tests with lyophilized M. aeruginosa NRC-1 cells have been conducted using mice, guinea pigs, rabbits, chickens, ducks, two calves and one lamb as the test animals.

The symptoms and pathological changes are described. On an equivalent weight basis it required three to five times the oral dosage to kill the large animals and birds as it did to kill the laboratory animals. The symptoms were less pronounced and the survival times were longer in the more resistant animals. Enlargement and congestion of the liver with necrosis of the hepatic cells were constant and pathognomonic. These findings are in general agreement with the observations of other workers who have examined the toxicity of naturally occurring Microcystis waterblooms.

The toxicities and structures of microcystin and of six other biologically active cyclic polypeptides are summarized. The pathological effects produced by microcystin in laboratory and domestic animals resemble those produced in man but differ from those produced in animals by the toxic peptides of Amanita phalloides.

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Eight sheep were given daily oral doses of copper sulphate until haemolysis occurred. Three of the sheep developed further periods of haemolysis after dosing ceased. Serum enzyme and urea levels were measured throughout the experiment and compared to those obtained from three undosed control sheep. Serum enzyme levels rose prior to haemolytic crises and urea levels rose subsequent to haemolysis in animals that died or were killed in extremis. Severe morphological changes were seen in liver, kidney and brain. Tissue levels of copper and iron were markedly elevated. It is concluded that tissue damage continues even after the cessation of ingestion of copper and that the damage can be severe enough to lead to repeated haemolytic crises.  相似文献   
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The phosphorothionate insecticide diazinon was incubated with liver microsomes from the sheep, cow, pig, guinea-pig, rat, turkey, chicken and duck. Metabolism by liver slices of most of these species was also examined. Hydroxydiazinon, isohydroxydiazinon, dehydrodiazinon, their oxons and diazoxon were identified and determined quantitatively or semi-quantitatively. An eighth metabolite was tentatively identified as the 6-aldehyde analogue of diazinon. Yields and rates of production of these metabolites varied greatly between species. Production of oxons was not generally correlated with susceptibility to diazinon poisoning, although it was lowest in the least susceptible animal, the sheep. The degradation of oxons by liver slices was too slow to explain the low toxicity of diazinon to the mammals. The relative importance of hepatic and extrahepatic metabolism in determining toxicity to vertebrates is discussed.  相似文献   
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