The effects of extremely low-frequency pulsed electromagnetic fields on analgesia in the nitric oxide pathway. Author: Demirkazik A1, Ozdemir E2, Arslan G3, Taskiran AS2, Pelit A4 Affiliation: <sup>1</sup>Departments of Biophysics, School of Medicine, Cumhuriyet University, Sivas, Turkey. Electronic address: dmrkzk@yahoo.com. <sup>2</sup>Departments of Physiology, School of Medicine, Cumhuriyet University, Sivas, Turkey. <sup>3</sup>Departments of Physiology, School of Medicine, Ondokuz Mayıs University, Samsun, Turkey. <sup>4</sup>Cukurova University, Faculty of Medicine, Department of Biophysics, Adana, Turkey. Conference/Journal: Nitric Oxide. Date published: 2019 Aug 10 Other: Pages: S1089-8603(19)30028-X , Special Notes: doi: 10.1016/j.niox.2019.08.003. [Epub ahead of print] , Word Count: 250 There is growing interest in the effects of extremely low-frequency electromagnetic fields on mechanisms in biological organisms. This study's goal is to determine the role of the Nitiric Oxide (NO) pathway for thermal pain by intentionally interfering with it using a pulsed electromagnetic field generated by an extremely low-frequency alternating current (ELF-PEMF) in combination with BAY41-2272 (sGC activator), NOS inhibitor l-NAME, and NO donor l-arginine. This study included 72 adult male Wistar albino rats (mean weight of 230 ± 12 g). The rats were kept at room temperature (22 ± 2 °C) in a 12-h light/dark cycle and in a room with sound insulation. PEMF (50 Hz, 5 mT) were applied four times a day for 30 min and at 15-min intervals for 15 days. Analgesic effects were assessed with tail-flick and hot-plate tests. Before the tests, NO donor l-arginine (300 mg/kg), sGC activator BAY41-2272 (10 mg/kg), and NOS inhibitor l-name (40 mg/kg) were injected intraperitoneally into rats in six randomly-selected groups. The maximum analgesic effect of a 5 mT electromagnetic field was on day 7. PEMF significantly increased the analgesia effect when the functioning of the NO pathway was ensured with l-arginine, which is a NO donor, and BAY41-2271, which is the intracellular receptor and sGC activator. However, there was no difference between rats treated with PEMF and the NOS inhibitor l-NAME as compared to rats only treated with PEMF. In conclusion, PEMF generate analgesia by activating the NO pain pathway. Copyright © 2019. Published by Elsevier Inc. KEYWORDS: Analgesia; Electromagnetic field; Nitric oxide pathway; Rats PMID: 31408675 DOI: 10.1016/j.niox.2019.08.003