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The Effect of Experimental Methyl Mercury Poisoning on the Number of Sulfhydryl (SH) Groups in the Brain, Liver and Muscle of Rat
Inverkan av experimentell metylkvicksilverförgiftning på mängden av sulfhydrylgrupper (SH) i hjärna, lever och muskel hos råtta
Acta Veterinaria Scandinavica volume 12, pages 551–559 (1971)
Summary
Fifteen adult male rats, the “experimental” rats, were fed a daily diet which contained methyl mercury hydroxide combined with liver homogenate. The daily dose of methyl mercury in terms of metallic mercury was 1.8 mg per rat. Six similar rats, the “controls”, were fed the same diet without methyl mercury. After the experimental rats had developed symptoms typical of methyl mercury poisoning, which occurred on the 15th day of the experiment, all the test animals were decapitated. The average total dose of methyl mercury producing toxic symptoms was 58,1 ± 6.1 mg Hg per kg body weight. The sulfhydryl groups and the mercury content of the brains, livers and caudal femoral muscles of the animals were determined. The SH determinations were made by amperometric titration and the mercury determinations by neutron activation analysis.
The mean number of SH groups in the brains (14.95 ± 1.97 µM/g) and livers (35.89 ± 4.10 µM/g) of the methyl mercury-fed rats was found to be significantly (P < 0.001 and P < 0.01 respectively) lower than the corresponding means of the livers (17.63 ± 1.12 µM/g) and brains (44.75 ± 5.60 µM/g) of the controls. The number of SH groups in the muscles did not differ significantly between the animal groups (0.5 < P < 0.6). The mean mercury content of the brains, livers and muscles was found to be 26.0, 124.6 and 39.1 p.p.m. respectively, corresponding to 0.12, 0.62 and 0.19 µM per g of tissue. The decrease in the number of SH groups in the brains, 2.68 µM/g, and in the livers, 8.86 µM/g, of the methyl mercury-fed rats is thus considered to be due mainly to other effects of methyl mercury than to the direct binding of this compound to the tissue SH groups.
Sammanfattning
Femton hanråttor utfodrades dagligen med ett foder som innehöll metylkvicksilverhydroksid blandat med leverhomogenat. Sex råttor, „kontrollerna”, fick samma foder utan metylkvicksilver. Den dagliga dosen av metylkvicksilver uttryckt i Hg per råtta var 1,8 mg. Då djuren efter femton utfodringsdagar visade för metylkvicksilverförgiftning typiska symptom, avlivades de och deras hjärnor, levrar och delar av kaudala femorala muskler tilvaratogs för kvicksilver- och sulfhydrylgruppbestämning. Den åt råttorna utfodrade totala medelmängden metylkvicksilver var då 58,1 ± 6,1 mg Hg per kg kroppsvikt.
Sulfhydrylbestämningarna utfördes genom amperometrisk titration och kvicksilveranalyserna medels neutronaktiveringsanalys.
Hjärnornas genomsnittliga mängd av SH grupper var 14,95 ± 1,97 μM/g och levrarnas 35,89 ± 4,10 μM/g hos de med metylkvicksilver utfodrade råttorna. Motsvarande genomsnittsvärden hos kontrollerna var 17,63 ± 1,12 nM/g i hjärnan och 44,75 ± 5,60 μM/g i levern. Differensen mellan genomsnittsvärden för hjärnorna (2,68 μM/g) och för levrarna (8,86 μM/g) var statistiskt signifikant (P < 0,001 för hjärnorna och P < 0,01 för levrarna), vilket ej var fallet med musklernas SH grupper, där metylkvicksilver ej förorsakade någon statistiskt signifikant förändring i SH gruppernas mängd (0,5 < P < 0,6). Hjärnornas genomsnittliga Hg mängd var 26,0, levrarnas 124,6 och musklernas 39,1 mg/kg hos metylkvicksilvergruppen motsvarande 0,12, 0,62 och 0,19 μM per g vävnad. Förminskningen av hjärnornas och levrarnas mängd av SH grupper hos metylkvicksilverr åttor na (2,68 μM/g resp. 8,86 μM/g) beror alltså på andra verkningar av metylkvicksilver än på den direkta bindningen av denna förening till SH grupperna.
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Pekkanen, T.J., Sandholm, M. The Effect of Experimental Methyl Mercury Poisoning on the Number of Sulfhydryl (SH) Groups in the Brain, Liver and Muscle of Rat. Acta Vet Scand 12, 551–559 (1971). https://doi.org/10.1186/BF03547723
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DOI: https://doi.org/10.1186/BF03547723