Ornithine decarboxylation in rat liver nuclei.
1. Decarboxylation of ornithine in rat liver cytosol produces putrescine; on the contrary, no putrescine is formed in nuclei. 2. In nuclei, decarboxylation is not inhibited by alpha-difluoromethylornithine and depends on NADH reoxidation. This shows that decarboxylation occurs after transamination of ornithine. 3. The increase of ornithine transaminase activity may be partially responsible for the enhanced decarboxylation after 1-methyl-3-isobutylxanthine administration. Data obtained in the presence of Ca2+ suggest that modification of nuclear Ca2+ concentration may also be responsible.
D015056:1-Methyl-3-isobutylxanthine / Q000378:metabolism; D000818:Animals; D002245:Carbon Dioxide / Q000494:pharmacology; D002262:Carboxy-Lyases / Q000378:metabolism*; D002467:Cell Nucleus / Q000201:enzymology*; D003600:Cytosol / Q000378:metabolism; D008099:Liver / Q000201:enzymology*; D008297:Male; D009955:Ornithine Decarboxylase / Q000378:metabolism*; D011700:Putrescine / Q000494:pharmacology; D051381:Rats
D002245:Carbon Dioxide; D002262:Carboxy-Lyases; D009955:Ornithine Decarboxylase; D015056:1-Methyl-3-isobutylxanthine; D011700:Putrescine