Effects of Reactive Oxygen Species and Nitrogen Species on the Excitability of Spinal Substantia Gelatinosa Neurons.
10.11620/IJOB.2016.41.3.141
- Author:
Joo Young PARK
1
;
Areum PARK
;
Sang Woo CHUN
Author Information
1. Department of Oral Physiology, College of Dentistry, Institute of Wonkwang Biomaterial and Implant, Wonkwang University, Iksan 570-749, Korea. physio1@wonkwang.ac.kr
- Publication Type:Original Article
- Keywords:
substantia gelatinosa neuron;
superoxide;
nitric oxide;
excitation;
patch clamp
- MeSH:
Adenine;
Animals;
Humans;
Membranes;
Microscopy, Confocal;
Neurons*;
Nitric Oxide;
Nitrogen*;
Perfusion;
Peroxynitrous Acid;
Rats;
Reactive Oxygen Species*;
Spinal Cord;
Spinal Cord Dorsal Horn;
Substantia Gelatinosa*;
Superoxide Dismutase;
Superoxides;
Tissue Donors;
Xanthine;
Xanthine Oxidase
- From:International Journal of Oral Biology
2016;41(3):141-147
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
Reactive oxygen species (ROS) and nitrogen species (RNS) are both important signaling molecules involved in pain transmission in the dorsal horn of the spinal cord. Xanthine oxidase (XO) is a well-known enzyme for the generation of superoxide anions (O₂˙⁻), while S-nitroso-N-acetyl-DL-penicillamine (SNAP) is a representative nitric oxide (NO) donor. In this study, we used patch clamp recording in spinal slices of rats to investigate the effects of O₂˙⁻ and NO on the excitability of substantia gelatinosa (SG) neurons. We also used confocal scanning laser microscopy to measure XO- and SNAP-induced ROS and RNS production in live slices. We observed that the ROS level increased during the perfusion of xanthine and xanthine oxidase (X/XO) compound and SNAP after the loading of 2',7'-dichlorofluorescin diacetate (H₂DCF-DA), which is an indicator of intracellular ROS and RNS. Application of ROS donors such as X/XO, β-nicotinamide adenine dinucleotide phosphate (NADPH), and 3-morpholinosydnomimine (SIN-1) induced a membrane depolarization and inward currents. SNAP, an RNS donor, also induced membrane depolarization and inward currents. X/XO-induced inward currents were significantly decreased by pretreatment with phenyl N-tert-butylnitrone (PBN; nonspecific ROS and RNS scavenger) and manganese(III) tetrakis(4-benzoic acid) porphyrin (MnTBAP; superoxide dismutase mimetics). Nitro-L-arginine methyl ester (NAME; NO scavenger) also slightly decreased X/XO-induced inward currents, suggesting that X/XO-induced responses can be involved in the generation of peroxynitrite (ONOO⁻). Our data suggest that elevated ROS, especially O₂˙⁻, NO and ONOO⁻, in the spinal cord can increase the excitability of the SG neurons related to pain transmission.
