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-DLpenicillamine (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.

서 론
 재료 및 방법
  척수절편 제작
  실험용액
  전기생리학적 기록방법
  형광이미지 측정
  실험자료의 분석
 연구성적
  척수 후각세포에서 X/XO, SNAP 투여에 의한 활성산소량 변화
  척수 후각세포 흥분성에 대한 X/XO, SNAP 투여의효과
 고 찰
 References

• Joo Young Park(Dept. of Oral Physiology, College of Dentistry, Institute of Wonkwang Biomaterial and Implant, Wonkwang University, Iksan 570-749)
• Areum Park(Dept. of Oral Physiology, College of Dentistry, Institute of Wonkwang Biomaterial and Implant, Wonkwang University, Iksan 570-749)
• Sang Woo Chun(Dept. of Oral Physiology, College of Dentistry, Institute of Wonkwang Biomaterial and Implant, Wonkwang University, Iksan 570-749)