BACKGROUND: Reactive oxygen species (ROS) is known to be involved in chronic and persistent pain.By using the ROS scavenger 5,5-dimethyl-1-pyrroline N-oxide (DMPO), we studied the effects of ROS on formalin-induced nociception in rats. METHODS: 5% formalin was injected in the left hind paw after intraperitoneal injection of saline or various doses of DMPO (10 mg/kg, 30 mg/kg, 100 mg/kg).Number of flinches was measured in a 5 minute interval for 1 hour. RESULTS: Formalin injected into the left hind paw induced a biphasic nociceptive behaviour. Intraperitoneal injection of DMPO diminished nociceptive behaviors dose-dependently during phase 2 but not phase 1. CONCLUSIONS: ROS might be involved in central sensitization and DMPO, a ROS scavenger, posses antinociceptive property in rats subjected to formalin induced hyperalgesia.
Animals ; Central Nervous System Sensitization ; Formaldehyde ; Injections, Intraperitoneal ; Nociception ; Pain Measurement ; Rats ; Reactive Oxygen Species

PURPOSE: The aim of this study was to analyze anatomical popliteal artery entrapment syndrome (PAES) and to individualize the treatment of this condition according to the anatomical status of the artery and the adjacent structure. METHODS: A total of 35 anatomical PAES legs in 23 consecutive patients treated within the Asan Medical Center, Seoul, Korea between 1995 and 2011 were analyzed retrospectively. Anatomical PAES was diagnosed by MRI and/or CT scans of the knee joint, and CT or conventional transfemoral arteriography of the lower extremities. RESULTS: We noted a type II gastrocnemius medial head (GNM) anomaly, a type III GNM anomaly, or an aberrant plantaris muscle in 51.4%, 20%, and 28.6% of PAES legs, respectively. In assessments of the arterial lesions, popliteal or tibial artery occlusion was noted in 19 of 26 symptomatic PAES legs. For cases without popliteal artery lesions, myotomy of the anatomically deranged muscle was performed in 5 of 7 symptomatic and 4 of 9 asymptomatic PAES legs. For occluded popliteal arteries, we performed ten direct repairs of the pathological popliteal artery and 4 femoro-below the knee popliteal bypass surgeries. As a result of the arterial Surgery, 9 direct procedures with myotomy yielded a patent artery, while 3 graft failures were noted in the bypass group. The median follow-up period was 84 months (range, 12–206 months). CONCLUSION: We recommend that treatment of PAES should be individualized based on pathology, symptoms, and various imaging studies.
Angiography ; Arteries ; Chungcheongnam-do ; Follow-Up Studies ; Head ; Humans ; Knee ; Knee Joint ; Korea ; Leg ; Lower Extremity ; Magnetic Resonance Imaging ; Muscle, Skeletal ; Pathology ; Popliteal Artery* ; Retrospective Studies ; Seoul ; Tibial Arteries ; Tomography, X-Ray Computed ; Transplants