title: Oral relaxin maintains intestinal blood flow in a rat model of NEC.
abstract: OBJECTIVE
  Intestinal vasoconstriction is a critical step in development of necrotizing enterocolitis (NEC). Relaxin (RLXN), a hormone found in breast milk but absent from formula, is a potent vasodilator. We hypothesized that relaxin-supplemented feeds with an NEC protocol would decrease NEC severity and increase intestinal blood flow.
  
  
  METHODS
  Timed-pregnant Sprague-Dawley rats were randomly assigned to CONTROL, NEC, NEC+1xRLXN, or NEC+All Feeds RLXN, and all but CONTROL underwent NEC protocol. NEC+1xRLXN and NEC+All Feeds RLXN groups were fed relaxin-supplemented formula with the last feed or every feed. At 48h of life, intestinal blood flow was measured at baseline and after application of 2.5% Delflex® solution.
  
  
  RESULTS
  The addition of relaxin to NEC group feeds (1x or All Feeds) improved the degree of ileal injury. Ileal blood flow was decreased in the NEC pups compared to the CONTROLS, but the addition of relaxin to one feed increased baseline ileal blood flow in the NEC group compared to NEC alone. Furthermore, the addition of relaxin to ALL feeds significantly increased baseline ileal blood flow.
  
  
  CONCLUSIONS
  Pups who received relaxin with all feeds had substantially increased ileal perfusion compared to control pups. Our data suggest that relaxin supplementation maintains intestinal blood flow and results in less histologic NEC.
authors.affiliation: Robley Rex Veterans Affairs Medical Center at Louisville, KY; Hiram C. Polk, Jr., M.D. Department of Surgery, University of Louisville, Louisville, KY.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Matheson
authors.affiliation: Hiram C. Polk, Jr., M.D. Department of Surgery, University of Louisville, Louisville, KY.
authors.forename: Sarah K
authors.initials: SK
authors.lastname: Walker
authors.affiliation: Hiram C. Polk, Jr., M.D. Department of Surgery, University of Louisville, Louisville, KY.
authors.forename: Alexandra C
authors.initials: AC
authors.lastname: Maki
authors.affiliation: Robley Rex Veterans Affairs Medical Center at Louisville, KY.
authors.forename: Saad P
authors.initials: SP
authors.lastname: Shaheen
authors.affiliation: Robley Rex Veterans Affairs Medical Center at Louisville, KY; Hiram C. Polk, Jr., M.D. Department of Surgery, University of Louisville, Louisville, KY.
authors.forename: R
authors.initials: R
authors.lastname: Neal Garrison
authors.affiliation: Division of Pediatric Surgery, Hiram C. Polk, Jr. M.D. Department of Surgery, University of Louisville, Louisville, KY. Electronic address: c0down01@louisville.edu.
authors.forename: Cynthia D
authors.initials: CD
authors.lastname: Downard
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000831:Animals, Newborn; D004195:Disease Models, Animal; D020345:Enterocolitis, Necrotizing / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D005260:Female; D007422:Intestines / Q000098:blood supply*; D017078:Laser-Doppler Flowmetry; D008833:Microcirculation / Q000187:drug effects / Q000502:physiology*; D011247:Pregnancy; D011270:Pregnancy, Animal; D051381:Rats; D017207:Rats, Sprague-Dawley; D012039:Regional Blood Flow / Q000187:drug effects*; D012065:Relaxin / Q000008:administration & dosage*; D014661:Vasoconstriction / Q000187:drug effects
chemical_list: D012065:Relaxin
keywords: Intestinal blood flow; Intestinal vasoconstriction; Necrotizing enterocolitis; Relaxin