Remote intrathecal morphine preconditioning is ineffective in the presence of neuraxial blockade with lidocaine.
Remote intrathecal morphine preconditioning (RMPC) induces cardioprotection via a neural pathway. Intrathecal lidocaine (LID) blocks spinal cord nerve transmission. This study examine whether LID prevents the effects of RMPC. Anesthetized, open chest, male Sprague-Dawley rats were assigned to one of seven treatment groups 3 days after intrathecal catheter placement. Rats from both RMPC and LID groups, respectively, received intrathecal morphine (3 μg/kg) and lidocaine (1%, 10 μL); morphine was administered by three cycles of 5-minute infusions interspersed with 5-minute infusion-free periods. The LID + RMPC group received the combination of LID and RMPC. Intrathecal naloxone methiodide (NM) (20 μg/kg) was administered either 15 minutes before RMPC, or 5 minutes before LID + RMPC. Ischemia and reperfusion injury were then induced by 30 minutes of left coronary artery occlusion, followed by 120 minutes of reperfusion. Infarct size, as a percentage of the area at risk (AAR), was determined by 2,3,5-triphenyltetrazolium staining. The RMPC and LID groups markedly reduced the infarct size (IS) compared with controls. LID prevented the effect of RMPC. NM had no effect on control and LID + RMPC treatments. However, NM pretreatment reversed cardioprotection of RMPC treatment. Intrathecal morphine preconditioning is ineffective in the presence of neuraxial blockade with lidocaine.
Department of Anesthesiology, Second Affiliated Hospital of Anhui Medical University, Hefei, China; Department of Anesthesiology, Third Affiliated Hospital of Anhui Medical University, Hefei, China.
Yao
Y
Lu
Department of Anesthesiology, University of Hong Kong, Hong Kong Special Administrative Region.
Gordon Tin Chun
GT
Wong
Department of Anesthesiology, Second Affiliated Hospital of Anhui Medical University, Hefei, China. Electronic address: zhangye_hassan@126.com.
Ye
Y
Zhang
Department of Anesthesiology, Second Affiliated Hospital of Anhui Medical University, Hefei, China.
Jun
J
Hu
Department of Anesthesiology, Third Affiliated Hospital of Anhui Medical University, Hefei, China.
Chunshan
C
Dong
D000818:Animals; D019157:Ischemic Preconditioning, Myocardial / Q000379:methods*; D008012:Lidocaine / Q000627:therapeutic use*; D008297:Male; D009020:Morphine / Q000627:therapeutic use*; D009270:Naloxone / Q000031:analogs & derivatives / Q000627:therapeutic use; D000644:Quaternary Ammonium Compounds / Q000627:therapeutic use; D051381:Rats; D017207:Rats, Sprague-Dawley
D000644:Quaternary Ammonium Compounds; D009270:Naloxone; C041269:N-methylnaloxone; D009020:Morphine; D008012:Lidocaine
Lidocaine; Morphine; Opioid receptors; Remote preconditioning; Spinal cord