Morphine prevents peroxynitrite-induced death of human neuroblastoma SH-SY5Y cells through a direct scavenging action.
N-ethyl-2-(1-ethyl-2-hydroxy-2-nitrosohydrazino)-ethanamine (NOC12), a nitric oxide donor, 3-morpholinosydnonimine (SIN-1), a generator of peroxynitrite (ONOO-), and peroxynitrite induced cell death accompanied by DNA fragmentation in human neuroblastoma SH-SY5Y cell cultures. Morphine prevented the cell death induced by SIN-1 or peroxynitrite, but not that induced by NOC12. The protective effect of morphine was concentration-dependent (10-100 microM), but was not antagonized by naloxone. The selective ligands for opioid receptor subtypes, [D-Ala2, N-Me-Phe4, Gly-ol5]enkephalin (DAMGO, micro-opioid receptor agonist), [D-Pen2,5]enkephalin (DPDPE, delta-opioid receptor agonist) and trans-(+/-)-3,4-dichloro-N-methyl-N-(2-[1-pyrrolidinyl]-cyclohexyl)benze neacetamide (U-50488, kappa-opioid receptor agonist) even at the concentration of 100 microM did not prevent the cell death induced by SIN-1. From measurement of the absorbance spectrum of peroxynitrite, the decomposition of peroxynitrite in 0.25 M potassium phosphate buffer (pH 7.4) was very rapid and complete within seconds. However, the absorbance was very stable in the presence of morphine. In addition, morphine inhibited peroxynitrite-induced nitration of tyrosine in a concentration-dependent manner. These results indicate that morphine rapidly reacts with peroxynitrite. The present study showed that morphine prevented peroxynitrite-induced cell death through its direct scavenging action, suggesting that morphine can protect cells against damage caused by peroxynitrite.
The Second Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Osaka University, Suita, Japan.
T
T
Kanesaki
M
M
Saeki
Y
Y
Ooi
M
M
Suematsu
K
K
Matsumoto
M
M
Sakuda
K
K
Saito
S
S
Maeda
D016923:Cell Death; D004347:Drug Interactions; D006801:Humans; D009020:Morphine / Q000378:metabolism / Q000494:pharmacology*; D009447:Neuroblastoma / Q000378:metabolism / Q000473:pathology*; D009566:Nitrates / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000494:pharmacology*; D009569:Nitric Oxide / Q000494:pharmacology; D017465:Receptors, Opioid, delta / Q000096:biosynthesis; D017473:Receptors, Opioid, kappa / Q000096:biosynthesis; D017450:Receptors, Opioid, mu / Q000096:biosynthesis; D014407:Tumor Cells, Cultured
D009566:Nitrates; D017465:Receptors, Opioid, delta; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu; C039642:peroxynitric acid; D009569:Nitric Oxide; D009020:Morphine