Metallic mercury uptake by catalase In Vitro metallic mercury uptake by rat liver dissociated cells, homogenate, cell components, heme protein and ferric ion, with the effect of ethyl and methyl alcohol on the uptake

In Vitro metallic mercury uptake by rat liver dissociated cells, homogenate, cell components (microbody-rich fraction, mitochondrial fraction and microsomal fraction), heme protein (catalase, cytochrome c, methemoglobin and hematine) and ferric ion were investigated. The effects of ethyl and methyl alcohol on the uptake were also investigated. The following results were obtained. 1) Mercury uptake by rat liver dissociated celld was similar to the uptake by homogenate. 2) Mercury uptake by rat liver homogenate in the presence of hydrogen peroxide was 1.22 times the uptake in the absence of hydrogen peroxide. The uptake by rat liver dissociated cells in the presence of hydrogen peroxide was similar to the uptake in the absence of hydrogen peroxide. 3) Mercury uptake by crystalline catalase, rat liver dissociated cells and homogenate was inhibited by ethtl alcohol and methyl alcohol, though inhibition of catalase activities was not observed. 4) Mercury uptake by rat liver cell components was observed in the order of microbody-rich fraction > microsomal fraction > mitochondrial fraction, and catalase activities were also observed in the order of microbody-rich fraction > microsomal fraction > mitochondrial fraction. Mercury uptake by rat liver cell components was inhibited by potassium cyanide and azide. 5) Cytochrome c, methemoglobin, catalase and ferric ion oxidized metallic mercury in the presence of hydrogen peroxide. In the absence of hydrogen peroxide, methemoglobin and ferric ion oxidized, but catalase and cytochrome c did not oxidize metallic mercury. 6) Hematine did not oxidize metallic mercury with or without hydrogen peroxide. 7) Uptake by ferric ion was inhibited by equimolar addition of EDTA. 8) In the presence of hydrogen peroxide, mercury uptake by catalase was 27,000 times, cytochrome c was 140 times and methemoglobin was 35 times the uptake by ferric ion. Therefore, of heme protein catalase showed the highest mercury uptake.