title: Comparison of 3-isobutyl-1-methylxanthine-induced accumulation of putrescine in rat pancreas and liver.
abstract: 3-Isobutylmethylxanthine (IBMX), a potent phosphodiesterase inhibitor, causes accumulation of putrescine of same magnitude in rat pancreas and liver. IBMX produces increases of acetyl CoA: polyamine N'-acetyltransferase (PAT) and of ornithine decarboxylase (ODC) activities in both organs. However ODC activity is 300 times higher in liver than in pancreas. In the latter organ, there is a transient increase of N1-acetylspermidine, followed by a decrease of spermidine, alpha-Difluoromethylornithine (DFMO), a potent ODC inhibitor, impairs the accumulation of putrescine in liver but not in pancreas. These results suggest that in pancreas the accumulated putrescine is essentially formed from spermidine, via N1-acetylation and oxidation, while in liver it is formed from decarboxylation of ornithine. A possible involvement of cAMP in the stimulation of the polyamine interconversion pathway is discussed.
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology*; D000818:Animals; D000242:Cyclic AMP / Q000502:physiology; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009955:Ornithine Decarboxylase / Q000032:analysis; D010179:Pancreas / Q000187:drug effects / Q000378:metabolism*; D011700:Putrescine / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013806:Theophylline / Q000031:analogs & derivatives*
chemical_list: D013806:Theophylline; D000242:Cyclic AMP; D009955:Ornithine Decarboxylase; D015056:1-Methyl-3-isobutylxanthine; D011700:Putrescine