Antinociceptive effect of phenyl N-tert-butylnitrone, a free radical scavenger, on the rat formalin test.
10.4097/kjae.2012.62.6.558
- Author:
Young Kwon KO
1
;
Ann Misun YOUN
;
Boo Hwi HONG
;
Yoon Hee KIM
;
Yong Sup SHIN
;
Po Soon KANG
;
Keon Jung YOON
;
Won Hyung LEE
Author Information
1. Department of Anesthesiology and Pain Medicine, Chungnam National University School of Medicine, Daejeon, Korea. whlee@cnu.ac.kr
- Publication Type:Original Article
- Keywords:
Formalin test;
Neuropathic pain;
Phenyl N-tert-butylnitrone;
Rats;
Reactive oxygen species
- MeSH:
Acute Pain;
Animals;
Central Nervous System Sensitization;
Chronic Pain;
Formaldehyde;
Humans;
Hydrogen Peroxide;
Male;
Neuralgia;
Nitric Oxide;
Oxidative Stress;
Pain Measurement;
Proteins;
Rats;
Rats, Sprague-Dawley;
Reactive Oxygen Species;
Spinal Cord;
Superoxides;
Tyrosine
- From:Korean Journal of Anesthesiology
2012;62(6):558-564
- CountryRepublic of Korea
- Language:English
-
Abstract:
BACKGROUND: Reactive oxygen species (ROS) such as superoxide radicals, hydrogen peroxide, nitric oxide, and nitroperoxide, cause oxidative stress which interferes with normal cell functioning, resulting in cell damage. It is reported to be associated with chronic pain, especially neuropathic pain, and inflammatory pain. ROS is also closely related to central sensitization. Therefore, this study was designed to explore the effects of Phenyl N-tert-butylnitrone (PBN), an ROS scavenger, in acute, continuous, and increasing pain caused by central sensitization. METHODS: Male Sprague-Dawley rats were divided into 2 groups, an intraperitoneal group (IP) and an intrathecal group (IT), and once again divided into an experimental group and a control group. The experimental group was injected with Phenyl N-tert-butylnitrone (PBN), a free radical scavenger, either intraperitoneally or intrathecally. After inducing pain by injecting formalin into the hind paw, pain behaviors were measured. Lumbar enlargement immmunohistochemistry was performed to assess nitrotyrosine, an oxidative stress marker, to identify the degree of protein nitration. RESULTS: Both experimental groups of IP and IT showed statistically significant decreases in the number of flinches compared to the control group in phase 1 and 2. Immunohistochemical evaluation in the control group revealed an increase in nitrated proteins in the gray matter of the lumbar spinal cord, but a significant decrease in nitrated proteins in the gray matter of lumbar spinal cord of the experimental group. CONCLUSIONS: Intraperitoneal and intrathecal administration of PBN decreases analgesic behaviors, allowing us to believe that ROS is mainly responsible for acute pain and central sensitization.
