title: Dose-dependent neuroprotection of delta-opioid peptide [D-Ala(2), D-Leu(5)] enkephalin on spinal cord ischemia-reperfusion injury by regional perfusion into the abdominal aorta in rabbits.
abstract: OBJECTIVE
  In our prior study, we showed that delta-opioid peptide [D-Ala(2), D-Leu(5)] enkephalin (DADLE), by regional perfusion into the abdominal aorta, could protect the spinal cord against ischemia-reperfusion (I/R) injury caused by aortic occlusion. However, the relative dose-response effects of DADLE still remain unclear. This study investigated whether DADLE has a dose-dependent efficiency on spinal cord I/R injury.
  
  
  METHODS
  New Zealand White rabbits were randomly divided into one of six groups: normal saline (NS; n = 8), DADLE (D) groups D0.0005 (n = 8), D0.005 (n = 8), D0.05 (n = 8), and D0.5 mg/kg (n = 8), and a sham group (n = 6). In the NS and DADLE groups, spinal cord ischemia was induced by infrarenal aortic occlusion for 30 minutes. During the occlusion, the same volume of NS or DADLE at the indicated doses was infused continuously through a catheter to the distally clamped abdominal aorta. Heart rate, blood pressure, and core temperature were monitored continuously to evaluate the potential adverse effects of DADLE. Neurologic behavioral function was assessed with the Tarlov scale system at 1, 6, 24, 48, and 72 hours after reperfusion. Neuronal injury evaluation in the ventral horn of the gray matter was evaluated by counting the normal motor neurons at 72 hours after reperfusion.
  
  
  RESULTS
  The therapeutic benefits increased at the doses of DADLE from 0.0005 to 0.05 mg/kg and decreased at 0.5 mg/kg, whereas the hemodynamic parameter was suppressed temporarily at the dose of 0.5 mg/kg.
  
  
  CONCLUSIONS
  These data revealed that regional administration of DADLE through the abdominal aorta provided dose-dependent protection on spinal cord I/R in rabbits.
authors.affiliation: Department of Anesthesiology, Shanghai First People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Haitong
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Anesthesiology, Shanghai First People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Binbin
authors.initials: B
authors.lastname: Chen
authors.affiliation: Department of Anesthesiology, Shanghai First People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Shitong
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Anesthesiology, Shanghai First People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. Electronic address: sunshineyao@163.com.
authors.forename: Junyan
authors.initials: J
authors.lastname: Yao
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000503:physiopathology / Q000601:surgery*; D002406:Catheterization, Peripheral; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D016308:Enkephalin, Leucine-2-Alanine / Q000008:administration & dosage*; D005260:Female; D007262:Infusions, Intravenous; D008026:Ligation; D008297:Male; D009046:Motor Neurons / Q000187:drug effects / Q000473:pathology; D018696:Neuroprotective Agents / Q000008:administration & dosage*; D011817:Rabbits; D012039:Regional Blood Flow; D015427:Reperfusion Injury / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D020760:Spinal Cord Ischemia / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D013997:Time Factors
chemical_list: D018696:Neuroprotective Agents; D016308:Enkephalin, Leucine-2-Alanine