Effect of cobalt on the synthesis and degradation of hepatic catalase in vivo.
1. The administration of CoCl(2) to rats caused a decrease in hepatic catalase activity as well as a decrease in the amount of catalase protein as measured by immunological assay. The mitochondrial enzyme decreased progressively over 2 days, whereas the cytosol enzyme decreased over 12h and then remained essentially unchanged for 2 days after a single injection of cobalt. 2. Incorporation of [(14)C]glycine into catalase haem was dramatically decreased by a single injection of cobalt, but that into catalase protein remained essentially unaltered. 3. Incorporation of [(3)H]leucine into liver protein increased in rats in a steady state receiving a daily injection of cobalt, which was in contrast with a marked inhibition observed in 5-amino[(3)H]laevulinate incorporation. 4. The initial rate of [(3)H]leucine incorporation into mitochondrial and cytosol catalase did not alter or was slightly depressed in the cobalt-treated animals, whereas the incorporation of 5-amino[(3)H]laevulinate into mitochondrial and cytosol catalase was conspicuously decreased, indicating that haem synthesis was limiting catalase formation. 5. The degradation rate of catalase protein, as measured by a double-labelling method, was not changed by the cobalt treatment.
D000622:Aminolevulinic Acid / Q000378:metabolism; D000818:Animals; D002374:Catalase / Q000096:biosynthesis / Q000378:metabolism*; D003035:Cobalt / Q000008:administration & dosage / Q000494:pharmacology*; D003600:Cytosol / Q000201:enzymology; D005998:Glycine / Q000378:metabolism; D006418:Heme / Q000096:biosynthesis; D007700:Kinetics; D007930:Leucine / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D008930:Mitochondria, Liver / Q000201:enzymology; D051381:Rats
D003035:Cobalt; D006418:Heme; D000622:Aminolevulinic Acid; D002374:Catalase; D007930:Leucine; D005998:Glycine