Is intrathecal magnesium sulfate safe and protective against ischemic spinal cord injury in rabbits?
We performed three sets of experiments to investigate the safety of intrathecal magnesium and to determine its optimal dose for protection, if any, against ischemic spinal cord injury in rabbits. First, we examined neurotoxicity of 0.3, 1, 2, or 3 mg/kg of magnesium sulfate (n = 6 each). Significant sensory dysfunction was observed in the 3-mg/kg group 7 days after administration. Motor dysfunction was found in two rabbits in both the 2- and 3-mg/kg groups. The area of destruction in laminae V-VII was observed in one, two, and one rabbit in the 1-, 2-, and 3-mg/kg groups, respectively. Second, we investigated the temporal profile (6 h, 48 h, and 96 h [n = 3 each]) of histopathologic changes after 3 mg/kg of magnesium sulfate and confirmed similar changes in the rabbits with motor dysfunction at 48 and 96 h. Third, we evaluated the effects of 0.3 mg/kg or 1 mg/kg of magnesium sulfate or saline (n = 6 each) administered before ischemia on hindlimb motor function and histopathology after spinal cord ischemia (15 min). Magnesium did not improve neurologic or histopathologic outcome 96 h after reperfusion. The results indicate that intrathecal magnesium has a risk of neurotoxicity and shows no evidence of protective effects against ischemic spinal cord injury.
Saeki
Hiroshi
H
Department of Anesthesiology-Resuscitology, Yamaguchi University School of Medicine, Japan.
Matsumoto
Mishiya
M
Kaneko
Shuichi
S
Tsuruta
Shunsuke
S
Cui
Ying Jun
YJ
Ohtake
Kazunobu
K
Ishida
Kazuyoshi
K
Sakabe
Takefumi
T
D000758:Anesthesia; D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D001831:Body Temperature / Q000502:physiology; D002452:Cell Count; D006614:Hindlimb / Q000502:physiology; D007278:Injections, Spinal; D008124:Locomotion / Q000502:physiology; D008278:Magnesium Sulfate / Q000008:administration & dosage / Q000627:therapeutic use*; D009046:Motor Neurons / Q000187:drug effects / Q000502:physiology; D018696:Neuroprotective Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D011817:Rabbits; D015427:Reperfusion Injury / Q000473:pathology / Q000517:prevention & control*; D012677:Sensation / Q000502:physiology; D013116:Spinal Cord / Q000473:pathology; D013119:Spinal Cord Injuries / Q000473:pathology / Q000517:prevention & control*; D020760:Spinal Cord Ischemia / Q000473:pathology / Q000517:prevention & control*
D018696:Neuroprotective Agents; D008278:Magnesium Sulfate