Association for Academic Surgery Synergetic induction of NGF with diazoxide and erythropoietin attenuates spinal cord ischemic injury Katsuhiro Yamanaka, MD, PhD,* Mohamed Eldeiry, MD, Muhammad Aftab, MD, Thomas J. Ryan, BS, Xianzhong Meng, MD, PhD, Michael J. Weyant, MD, David A. Fullerton, MD, and T. Brett Reece, MD Division of Cardiothoracic Surgery, The Department of Surgery, University of Colorado, Aurora, Colorado article info Article history: Received 27 February 2018 Received in revised form 25 May 2018 Accepted 10 July 2018 Available online xxx Keywords: Spinal cord Ischemia reperfusion injury Neurotrophin Diazoxide Erythropoietin Paraplegia abstract Background: Paraplegia remains a significant complication of thoracoabdominal aortic intervention. We previously reported that diazoxide (DZ), enhances the neuroprotective efficacy of erythropoietin (EPO). We hypothesized that DZ and EPO combined treatment attenuates spinal cord ischemic injury through upregulation of nerve growth factor (NGF). Methods: DZ (pretreatment) was given to adult male C57/BL6 mice by oral gavage and EPO (before surgery) was intraperitoneally injected 32 h after administration of DZ. Spinal cords were harvested 0, 2, 4, and 6 h after injection of EPO. NGF expression was analyzed by western blot. After determining the optimal time, NGF expression was compared between DZ (pretreatment) þ EPO (before surgery), DZ þ PBS, PBS þ EPO, and PBS þ PBS (ischemic control). Four groups were studied to compare the motor function after ischemia: DZ þ EPO (n ¼ 11), ischemic control (n ¼ 9), DZ þ EPO þ tropomyosin receptor kinase A receptor in- hibitor (n ¼ 9), and sham (without cross-clamp, n ¼ 4). Spinal cord ischemia was induced by a 4-min thoracic aortic cross-clamp. Functional scoring (Basso Mouse Score) was done at 12-h intervals until 48 h, and spinal cords were harvested for evaluation of NGF expression and histological changes. Results: NGF expression was significantly upregulated 4 h after administration of EPO. At 4 h after injection of EPO, NGF expression in the DZ þ EPO group was significantly higher than that in the other groups. DZ þ EPO significantly preserved motor function compared with all other groups. At 48 h after reperfusion, the level of NGF expression in the DZ þ EPO group, was significantly higher than in all other groups. Conclusions: DZ þ EPO attenuates spinal cord ischemic injury through upregulation of NGF. Better understanding of this mechanism may serve to further prevent ischemic complications for aortic intervention. Published by Elsevier Inc. * Corresponding author. University of Colorado, Cardiothoracic Surgery, Mail Stop C310, 12631 East 17th Avenue, Room 6601, Aurora, CO 80045. Tel.: þ1 3037242798; fax: þ1 3037242806. E-mail address: yamakachubanzai@gmail.com (K. Yamanaka). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.JournalofSurgicalResearch.com journal of surgical research  january 2019 (233) 124 e131 0022-4804/$ e see front matter Published by Elsevier Inc. https://doi.org/10.1016/j.jss.2018.07.021