Nitric oxide scavenger carboxy-PTIO potentiates the inhibition of dopamine uptake by nitric oxide donors.
2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (carboxy-PTIO) has been increasingly used as nitric oxide (NO) scavenger. Carboxy-PTIO reacts with NO to form nitric dioxide and 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl (carboxy-PTI). In rat C6 glioma cells expressing human dopamine transporter, carboxy-PTIO paradoxically potentiated the inhibition of [(3)H]dopamine uptake by two NO donors, diethylamine/NO and (Z)-1-[N-(3-ammoniopropyl)-N-(n-propyl)-amino]/NO. Further examinations revealed that carboxy-PTI concentration-dependently reduced dopamine uptake, indicating that the formation of carboxy-PTI may account for the failure of carboxy-PTIO to abolish NO elicited effects. These results suggest that caution should be taken in interpreting data obtained using carboxy-PTIO and probably other NO scavengers.
Department of Biomedical and Therapeutic Sciences, University of Illinois College of Medicine, Peoria, IL 61656-1649, USA.
Bo-Jin
BJ
Cao
Maarten E A
ME
Reith
D000818:Animals; D001565:Benzoates / Q000494:pharmacology*; D004298:Dopamine / Q000493:pharmacokinetics*; D050483:Dopamine Plasma Membrane Transport Proteins; D004357:Drug Synergism; D005910:Glioma / Q000378:metabolism*; D007093:Imidazoles / Q000494:pharmacology*; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins / Q000187:drug effects*; D009419:Nerve Tissue Proteins; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D051381:Rats
D001565:Benzoates; D050483:Dopamine Plasma Membrane Transport Proteins; D007093:Imidazoles; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D020030:Nitric Oxide Donors; C079393:1,3-dihydroxy-4,4,5,5-tetramethyl-2-(4-carboxyphenyl)tetrahydroimidazole; D004298:Dopamine