TY - JOUR T1 - Intraesophageal Administration of GS-Nitroxide (JP4-039) Protects Against Ionizing Irradiation-induced Esophagitis JF - In Vivo JO - In Vivo SP - 811 LP - 819 VL - 24 IS - 6 AU - MICHAEL W. EPPERLY AU - JULIE P. GOFF AU - SONG LI AU - XIANG GAO AU - PETER WIPF AU - TRACY DIXON AU - HONG WANG AU - DARCY FRANICOLA AU - HONGMEI SHEN AU - JEAN-CLAUDE M. RWIGEMA AU - VALERIAN KAGAN AU - MARK BERNARD AU - JOEL S. GREENBERGER Y1 - 2010/11/01 UR - http://iv.iiarjournals.org/content/24/6/811.abstract N2 - Background/Aim: This study evaluated esophageal radioprotection by the Gramicidin S (GS) derived-nitroxide, JP4-039, a mitochondrial targeting peptide-isostere covalently-linked to 4-amino-Tempo, delivered in a novel swallowed oil-based (F15) formulation. Materials and Methods: C57BL/6HNsd female mice received intraesophageal F15 formulation containing JP4-039 (4 mg/ml in 100 μl volumes) 10 minutes before 28 or 29 Gy upper body irradiation compared to MnSOD-PL (100 μl containing 100 μg plasmid) 24 hours prior to irradiation. Subgroups received 1×107 C57BL/6HNsd, GFP+ male bone marrow cells intravenously 5 days after irradiation. Results: JP4-039/F15 or MnSOD-PL increased survival compared to irradiated controls (p<0.0001 for either). Marrow injection further increased survival (p=0.0462 and 0.0351, respectively). Esophagi removed at 1, 3, 7, 14, 24, or 60 days showed bone marrow-derived cells in the esophagi. Conclusion: Intraesophageal GS-nitroxide radioprotection is mediated primarily through recovery of endogenous esophageal progenitor cells. ER -