Reactive Oxygen Species and Nitrogen Species Differentially Regulate Neuronal Excitability in Rat Spinal Substantia Gelatinosa Neurons

Autor:	Areum Park, Hae In Lee, Sang Woo Chun
Rok vydání:	2014
Předmět:	chemistry.chemical_classification Reactive oxygen species Superoxide Depolarization Membrane hyperpolarization medicine.disease_cause chemistry.chemical_compound chemistry Biochemistry Biophysics medicine Patch clamp Xanthine oxidase Oxidative stress Intracellular
Zdroj:	International Journal of Oral Biology. 39:229-236
ISSN:	2287-6618 1226-7155
DOI:	10.11620/ijob.2014.39.4.229
Popis:	Reactive oxygen species (ROS) and nitrogen species (RNS) are implicated in cellular signaling processes and as a cause of oxidative stress. Recent studies indicate that ROS and RNS are important signaling molecules involved in nociceptive transmission. Xanthine oxidase (XO) system is a well-known system for superoxide anions (O2˙-) generation, and sodium nitroprusside (SNP) is a representative nitric oxide (NO) donor. Patch clamp recording in spinal slices was used to investigate the role of O2˙- and NO on substantia gelatinosa (SG) neuronal excitability. Application of xanthine and xanthine oxidase (X/XO) compound induced membrane depolarization. Low concentration SNP (10μM) induced depolarization of the membrane, whereas high concentration SNP (1 mM) evoked membrane hyperpolarization. These responses were significantly decreased by pretreatment with phenyl N-tert-butylnitrone (PBN; nonspecific ROS and RNS scavenger). Addition of thapsigargin to an external calcium free solution for blocking synaptic transmission, led to significantly decreased X/XO-induced responses. Additionally, X/XO and SNP-induced responses were unchanged in the presence of intracellular applied PBN, indicative of the involvement of presynaptic action. Inclusion of GDP-β-S or suramin (G protein inhibitors) in the patch pipette decreased SNP-induced responses, whereas it failed to decrease X/XO-induced responses. Pretreatment with n-ethylmaleimide (NEM; thiol-alkylating agent) decreased the effects of SNP, suggesting that these responses were mediated by direct oxidation of channel protein, whereas X/XO-induced responses were unchanged. These data suggested that ROS and RNS play distinct roles in the regulation of the membrane excitability of SG neurons related to the pain transmission.
Databáze:	OpenAIRE
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