Altered thiol group status in the heart ornithine decarboxylase inactivated following perfusion with t-butylhydroperoxide.
1. The perfusion for 15 min of isolated rat hearts with 100 microM t-butylhydroperoxide leads to a 75% diminuition of the tissue GSH/GSSG ratio. 2. After t-butylhydroperoxide infusion, the isoproterenol-stimulated heart ODC was strongly inhibited. The addition of 2 mM DTT in the assaying buffer removed the ODC inactivation. 3. The inhibited ODC had an eluition profile similar to active ODC when chromatographed on a Sephacryl S-200 column; moreover, the ODC activity recovered after a thiol affinity chromatography as unbound fraction, was two times increased in the t-butylhydroperoxide perfused hearts in comparison to control. 4. The hearts perfused with 1 mM acetylcysteine after 15 min of perfusion with t-butylhydroperoxide recovered almost completely the initial ODC activity.
Guarnieri
C
C
Istituto di Chimica Biologica, Università di Bologna, Italy.
Flamigni
F
F
Rizzuto
S
S
Vaona
I
I
Caldarera
C M
CM
D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D005978:Glutathione / Q000378:metabolism; D066298:In Vitro Techniques; D009206:Myocardium / Q000201:enzymology*; D009955:Ornithine Decarboxylase / Q000378:metabolism*; D010545:Peroxides / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013438:Sulfhydryl Compounds / Q000032:analysis*; D020122:tert-Butylhydroperoxide
D010545:Peroxides; D013438:Sulfhydryl Compounds; D020122:tert-Butylhydroperoxide; D009955:Ornithine Decarboxylase; D005978:Glutathione; D000111:Acetylcysteine