Activation of cyclic GMP formation in mouse neuroblastoma cells by a labile nitroxyl radical. An electron paramagnetic resonance/spin trapping study.
The receptor-mediated generation of an endothelial-derived relaxing factor (EDRF)-free radical intermediate in a neuronal cell line detected by spin trapping techniques has been reported. Here we report the time course of the appearance of the 3,5-dibromo-4-nitrosobenzene sulfonate (DBNBS) spin adduct and cyclic GMP formation following addition of carbamylcholine to suspensions of cultured mouse neuroblastoma cells (clone N1E-115). The time course of the appearance of the DBNBS spin adduct shows that spin adduct formation decreases possibly reaching a minimum approximately between 35 and 40 s. This is inversely proportional to cGMP formation which reaches a maximum at approximately 40 s after carbamylcholine activation. In addition, the inhibitory effect of NG-monomethyl-L-arginine (NMMA), potassium ferricyanide, K3Fe(CN)6 and methylene blue in cytosol preparation was investigated. A mechanism is proposed that essentially accounts for the combined results observed by spin trapping/electron paramagnetic resonance (EPR) study providing direct evidence for the muscarinic receptor-mediated formation of a labile, diffusible precursor of nitric oxide (NO.) derived from L-arginine that activates soluble guanylate cyclase.
Veterans Administration Medical Center, Baltimore, MD 21218.
C M
CM
Arroyo
C
C
Forray
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology; D001557:Benzenesulfonates / Q000378:metabolism; D000242:Cyclic AMP / Q000096:biosynthesis*; D004578:Electron Spin Resonance Spectroscopy; D004789:Enzyme Activation; D005292:Ferricyanides / Q000494:pharmacology; D005609:Free Radicals / Q000494:pharmacology; D006162:Guanylate Cyclase / Q000378:metabolism; D008751:Methylene Blue / Q000494:pharmacology; D051379:Mice; D009249:NADP / Q000502:physiology; D009447:Neuroblastoma / Q000378:metabolism* / Q000473:pathology; D009589:Nitrogen Oxides / Q000494:pharmacology*; D009603:Nitroso Compounds / Q000378:metabolism; D011976:Receptors, Muscarinic / Q000502:physiology; D014407:Tumor Cells, Cultured; D019323:omega-N-Methylarginine
D001557:Benzenesulfonates; D005292:Ferricyanides; D005609:Free Radicals; D009589:Nitrogen Oxides; D009603:Nitroso Compounds; D011976:Receptors, Muscarinic; D019323:omega-N-Methylarginine; D009249:NADP; C048757:3,5-dibromo-4-nitrosobenzenesulfonate; D001120:Arginine; D000242:Cyclic AMP; D006162:Guanylate Cyclase; C039900:nitroxyl; D008751:Methylene Blue; C028033:potassium ferricyanide