Experimental Research Article Korean J Anesthesiol 2010 August 59(2): 104-110 DOI: 10.4097/kjae.2010.59.2.104 Antioxidant effect of lidocaine and procaine on reactive oxygen species-induced endothelial dysfunction in the rabbit abdominal aorta Jae Myeong Lee2, Jung Kook Suh1, Ji Seon Jeong1, Sang Yun Cho1, and Dong Won Kim1 Department of Anesthesiology and Pain Medicine, College of Medicine, 1Hanyang University, 2Catholic University of Korea, Seoul, Korea Background: Reactive oxygen species (ROS) induce lipid peroxidation and tissue damage in the endothelium. We tested the antioxidant effect of lidocaine and procaine on ROS-induced endothelial damage in the rabbit aorta. Methods: Aortic rings isolated from rabbits were suspended in an organ bath filled with Krebs-Henseleit (K- H) solution bubbled with 5% CO2 and 95% O2 at 37.5oC. After precontraction with phenylephrine (PE, 10-6 M), changes in tension were recorded following a cumulative administration of acetylcholine (ACh 3 × 10-8 to 10-6 M). Differences were measured as percentages of ACh-induced relaxation of aortic rings before and after exposure to ROS as generated by electrolysis of the K-H solution. The aortic rings were pretreated with lidocaine or procaine (10-5 M to 3 × 10-3 M) to compare their effects, as well as ROS scavengers, catalase, mannitol, sodium salicylate, and deferoxamine, and a catalase inhibitor, 3-amino-1,2,4-triazole (3AT). Results: Lidocaine and procaine dose-dependently maintained endothelium-dependent relaxation induced by ACh despite ROS activity (P < 0.05 vs control value). The 3AT pretreated procaine (3 × 10-3 M) group decreased more significantly than the un-pretreated procaine group (P < 0.05). Conclusions: These findings suggest that lidocaine and procaine dose-dependently preserve endothelium- dependent vasorelaxation against ROS attack, potentially via hydrogen peroxide scavenging. (Korean J Anesthesiol 2010; 59: 104-110) Key Words: Catalase, Endothelium, Lidocaine, Procaine, Reactive oxygen species, 3-amino-1,2,4-triazole. Received: April 28, 2010. Revised: 1st, May 3, 2010; 2nd, May 6, 2010. Accepted: May 6, 2010. Corresponding author: Jung Kook Suh, M.D., Department of Anesthesiology and Pain Medicine, College of Medicine, Hanyang University, 17, Haengdang-dong, Seongdong-gu, Seoul 133-792, Korea. Tel: 82-2-2290-8680, Fax: 82-2-2299-0742, E-mail: jksuh@hanyang.ac.kr The 86th Annual Scientific Meeting of The Korean Society of Anesthesiologists, Poster Session P-138. This is a theisis for a doctor's degree. CC This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http:// creativecommons.org/licenses/by-nc/3.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Copyright ⓒ Korean Society of Anesthesiologists, 2010 www.ekja.org