Alkylmercury Compounds Research Articles

Distribution of inorganic, aryl, and alkyl mercury compounds in rats

Mercuric chloride (MC), phenylmercuric chloride (PMC), ethylmercuric chloride (EMC), S-ethylmercuric cysteine (EMCys), and n-butylmercuric chloride (BMC) labeled with 203Hg were subcutaneously administered to rats, and the distribution and excretion of mercury were determined. In general, alkylmercury compounds (EMC, EMCys, and BMC) were excreted more slowly and were retained in higher concentration for a longer time in the body than MC and PMC. Several alkylmercury compounds revealed different metabolic behavior which depended on the carbon-chain length of the alkyl group. Distribution of mercury in the brain was found to depend on the structure of the mercury compounds. The relation between the neurotoxicity and the structure of the mercury compounds was discussed.

Use and residues of mercury compounds in agriculture.

Mercury compounds were first used in Germany as seed dressings to control seed-borne diseases of cereals about 1914. ‘Uspulun’, described as a ‘chlorophenolmercury’ compound was placed on the market in 1915 by Bayer A.G. as a liquid dressing and was soon widely used. Dusts, such as ‘Ceresan’, at first having phenylmercury acetate as the active ingredient and, subsequently, a methoxyethylmercury compound, and ‘Agrosan’, a tolylmercury acetate formulation, became more widely used ten years later. Liquid treatments, using alkylmercury active ingredients, were reintroduced about the time of World War II because of the reduced hazards and inconvenience to operators dressing the grain in specially designed machines, although alkylmercury compounds are more toxic than arylmercurials. In Sweden it has recently been found that the extensive use of alkylmercury compounds can lead to harmful contamination of the environment and there they have been replaced by other organomercury compounds. In most countries both liquid and dust treatments are commonly used. Formulations containing organo- mercurials have been found to give a better control of fungal diseases of grain than non-mercurial formulations.KeywordsFoliar SprayMercury ContentMercury CompoundApple PeelOrganomercury CompoundThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

1488. Alkylmercurial inhibits protein synthesis: Yoshino, Y., Mozai, T. & Nakao, K. (1966). Biochemical changes in the brain in rats poisoned with an alkylmercury compound, with special reference to the inhibition of protein synthesis in brain cortex slices. J. Neurochem.13, 1223

1488. Alkylmercurial inhibits protein synthesis: Yoshino, Y., Mozai, T. & Nakao, K. (1966). Biochemical changes in the brain in rats poisoned with an alkylmercury compound, with special reference to the inhibition of protein synthesis in brain cortex slices. J. Neurochem.13, 1223

Studies in Humans on the Distribution of Mercury in the Blood and the Excretion in Urine after Exposure to Different Mercury Compounds

Using neutron activation analysis the mercury concentration in blood of non-exposed control persons has been shown to be 6–12 ng/g. In a group of persons exposed to methyl mercury compounds the mercury content in whole blood was 70–180 ng/g, in plasma 3–10 ng/g. A group of persons exposed to metal mercury vapors had a mercury concentration in whole blood of 12–90 ng/g, in plasma 5–74 ng/g. The mercury concentration in urine was hardly increased in the alkyl mercury group but there was a fair increase in the metal mercury group.It is evident that the distribution of mercury in blood is quite different after exposure to different mercurials and so is the rate of excretion in urine. The distribution-excretion pattern may be used for diagnostic purposes.The excretion of mercury cannot be used to evaluate the exposure to alkyl mercury compounds.

Biochemical changes in the brain in rats poisoned with an alkymercury compound, with special reference to the inhibition of protein synthesis in brain cortex slices.

SUMMARYThe incorporation of [U‐14C]leucine into the protein of brain cortex slices from rats poisoned with methylmercury thioacetamide was markedly inhibited before the development of neurological symptoms and when the oxygen consumption, aerobic and anaerobic glycolysis and sulphydryl enzyme activities were unchanged.After the appearance of neurological symptoms, the oxygen consumption decreased significantly, while lactic acid formation did not change under anaerobic conditions, but slightly decreased under aerobic conditions.The activities of the three sulphydryl enzymes (Mg‐activated ATPase, fructose‐ diphosphate aldolase and succinate dehydrogenase) were almost the same in visual cortex, motor cortex, cerebellum and caudate nucleus, while the activities of Mg‐activated ATPase and succinate dehydrogenase in the white matter were lower than that in the grey matter. There was no difference in the activity of fructosediphosphate aldolase in grey and white matter. The activities of all three enzymes did not show any change in the earlier stage of poisoning when the animal remained free from neurological symptoms. At the more advanced stage, when neurological symptoms were present, only the activity of the succinate dehydrogenase decreased significantly, while the activities of the other two enzymes remained unchanged.The selective inhibition of protein synthesis may have a direct bearing on the poisoning by the alkylmercury compound.

Decarboxylation of mercury salts of organic acids under the action of peroxides and ultraviolet radiation

1. Under the action of peroxides or UV radiation mercuric alkanoates undergo initiated free-radical decarboxylation with formation of alkylmercury compounds. 2. For the lower alkanoates — mercuric acetate and propionate — the decarboxylation reaction has a chain character and provides a convenient method for the synthesis of organomercury compounds, particularly (alkanoyloxy) methylmercurys. 3. In the aromatic series the decarboxylation of mercuric salts goes much less readily. The introduction of a substituent into the aromatic nucleus hinders the decarboxylation of mercuric arenecarboxylates. 4. Mercurous carboxylates react with peroxy compounds with formation of organomercury compounds. The reaction is of preparative interest and can be applied for the fixation of free radicals in the liquid phase.

Fluoroolefins. XI. The Conversion of Fluoroolefins to Fluoroalkyl Nitroso Compounds via Alkylmercury Compounds

Fluoroolefins. XI. The Conversion of Fluoroolefins to Fluoroalkyl Nitroso Compounds via Alkylmercury Compounds

Studies on the organic mercury compound in the fish and shellfish from Minamata Bay as the causative agent of Minamata disease and the formation of the poison

Authors have observed that the shellfish from Minamata Bay ashed by heat was deprived of its toxicity to animals, so the causative agent of the Minamata disease was considered to be an organic compound. And then an alkyl mercury compound was proved in the fish and shellfish from the bay. It was proved experimentally that the alkyl mercury compound in the fish and shellfish was not synthesized from the inorganic mercury compounds accumulated in the mud of the drainage from Minamata Factory and the bay, and an alkyl mercury compound discharged in the bay had directly accumulated in the fish and shellfish. On the other hand, the waste treatment plant was completed at the beginning of 1960. Since then the mercury content in the fish and shellfish from the bay had gradually diminished, but in January of 1961 an organic mercury compound which was distilled with steam was proved from the mud in the drainage from the factory, but the organic mercury compound had diminished from the mud relatively in short time. The organic mercury compound proved from the mud of the drainage was considered that it was discharged from the factory, for the mercury content in the shellfish from the bay had temporarily increased at the same time.Then methyl mercury chloride (CH3HgCl) was extracted from the sludge accumulated in the reaction tube of the acetaldehyde plant of the factory and the same compound was extracted from the shellfish of the bay. Methyl mercury chloride (m.p. 174°C) have IR absorption spectra at 1191cm-1 and 788cm-1 and stable in acidic and alkaline solution and distilled with steam in acidic solution, and have low Rf value in the paperchromatography.Various methyl mercury compounds such as bis (methyl mercury) sulfide [(CH3Hg)2S], methyl (methylthio) mercury (CH3HgSCH3), methyl mercury hydroxide (CH3HgOH) and so on were synthesized for the purpose to know whether methyl mercury chloride discharged from the factory might have changed to another methyl mercury compound or not. But experimental results showed that methyl mercury chloride discharged from the factory had directly accumulated in the fish and shellfish of the bay.Further experiments proved that symptoms and findings of cats administered per os with the above described methyl mercury compounds were the same with those of animals administered with the fish and shellfish from the bay.From the above results it was concluded that the causative compound of the Minamata disease was methyl mercury chloride and the active agent for the development of the disease was methyl mercury radical (CH3Hg-).

607. Problems in assessing exposure to mercury: Berlin, M. (1963). On estimating threshold limits for mercury in biological material. Acta med. scand. Suppl. 396

607. Problems in assessing exposure to mercury: Berlin, M. (1963). On estimating threshold limits for mercury in biological material. Acta med. scand. Suppl. 396

Treatment of Skin Burns Due to Alkyl Mercury Compounds

Treatment of Skin Burns Due to Alkyl Mercury Compounds

Report II Comparison of the mercury compound in the shellfish from Minamata Bay with various mercury compounds experimentally accumulated in the control shellfish

In order to investigate the genesis of the poison in the fish and shellfish from Minamata Bay biological and chemical properties were compared with mercury compounds experimentally accumulated in the control shellfish.1) The mercury content in the shellfish Hormomya mutabilis (Gould) showed ca 100 ppm of dry weight at the end of 1959, but afterwards it decreased gradually and showed 30 ppm in August of 1960, probably on account of the completion of the waste treatment equipment of Minamata Factory. But in January of 1961, it increased again and showed 50 ppm, perhaps owing to the transitory suspension of the operation of the waste treatment.2) Toxicity of mercury compounds to the short necked clam-Venus japonica (Deshayes) was observed. Venus could survive for about 1 week in the sea water containing mercury compounds at the rate of 0.3 ppm as Hg, and the mercury content in Venus showed ca 40-50 ppm of dry weight. Na2S2O3 suppressed the toxicity of mercury compounds, but Ca-EDTA had no effect on it. The mercury content in Venus depended generally on the surviving period and not on the toxicity, but the accumulation of mercury in Venus cultured in the sea water containing alkyl mercury compounds had a tendency to be greater than that of other mercury compounds.3) The mercury content in organs of the shellfish from Minamata Bay was higher in the nervous nodules than in other organs. But the mercury content in organs of the shellfish cultured in the sea water containing HgCl2 was higher in the gills than in other organs.4) The shellfish Venus cultured in the sea water containing HgCl2 was administered to rats and mice. The distribution of mercury in organs of these animals had the higher content in the kidney and the liver.5) The shellfish cultured in the sea water containing inorganic and organic mercury compounds were digested with pepsin at pH 1.6 and the digests were distilled with steam and the mercury in the digested fluids and that transferred into distillates were observed. Mercury was found in digested fluids and distillates of the shellfish which was accumulated with alkyl mercury compounds, especially with methyl mercury and ethyl mercury, but not with other organic and inorganic mercury compounds.6) These results suggest that organic mercury compound accumulated in the shellfish has come directly from the sea water, and has not been synthesized from inorganic mercury compounds in the shellfish. And from results of the digestion and the steam distillation of the control shellfish cultured in the sea water containing many inorganic and organic mercury compounds, the organic mercury in the shellfish from Minamata Bay was supposed to be an alkylmercury compound, probably methyl or ethyl mercury compound.

Treatment of skin burns due to alkyl mercury compounds.

(1961). Treatment of Skin Burns Due to Alkyl Mercury Compounds. Archives of Environmental Health: An International Journal: Vol. 3, No. 5, pp. 592-593.

Poisoning by Methyl Mercury Compounds

In 1940 Hunter and others, reporting on cases of poisoning by methyl mercury compounds, showed that those working with certain organic mercury derivatives are exposed to great danger. In 1945 Herner collated the cases of poisoning by alkyl mercury compounds recorded in the literature. The seven cases hitherto published show a character istic clinical picture beginning with a sensation of numbness in the tongue and weakness of the hands and feet. Motor inco-ordination followed, and the faculty of walking and the power of speech rapidly deteriorated. Defective vision and hearing occurred in several cases, and there was often mental tor pidity, which led in some cases to complete dementia. During the war of 1939-45, when Sweden was virtually cut off from the rest of the world, the manufacture of methyl mercury compounds for use in seed-dressing and wood-preserving was taken up. In consequence of this certain hygienic problems arose as well as a number of typical cases of poison ing, two of which ended fatally. A report on these experiences seems justified. First the condition of the premises will be described at the time when the accidents took place, after which a series of cases will be presented. Finally the preventive measures adopted will be discussed.