Bilirubin production and conjugation from newly formed heme in isolated rat hepatocytes.
1. Heme synthesis from delta-aminolevulinic acid (delta-ALA) in freshly isolated rat hepatocytes was maximal at 100 microM with a rate of approx. 7 nmol being synthesized per g wet weight cells. 2. Approximately 8% of synthesized heme was converted to bilirubin and 50% of the newly synthesized bilirubin was conjugated. 3. The ratio of di to monoconjugate was approx. 2.5. Incorporation of delta-ALA into bilirubin was increased by additional delta-ALA, heme and was also doubled in cells isolated from animals treated with CoCl2. 4. Bilirubin formation was inhibited approx. 90% by in vitro treatment with heme oxygenase inhibitors zinc and tin protoporphyrin.
Rodgers
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PA
Department of Physiological Sciences, School of Veterinary Medicine, University of California, Davis 95616.
Cornelius
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CE
Freedland
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RA
D000622:Aminolevulinic Acid / Q000378:metabolism; D000818:Animals; D001654:Bile Pigments / Q000378:metabolism; D001663:Bilirubin / Q000096:biosynthesis / Q000378:metabolism*; D002478:Cells, Cultured; D003035:Cobalt / Q000494:pharmacology; D006418:Heme / Q000378:metabolism*; D006427:Hemin / Q000502:physiology; D007700:Kinetics; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D008297:Male; D008665:Metalloporphyrins / Q000494:pharmacology; D011524:Protoporphyrins / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
D001654:Bile Pigments; D008665:Metalloporphyrins; D011524:Protoporphyrins; C017803:zinc protoporphyrin; D003035:Cobalt; D006418:Heme; D006427:Hemin; D000622:Aminolevulinic Acid; C032628:tin protoporphyrin IX; C018021:cobaltous chloride; D001663:Bilirubin