Effects of ketamine on the balance of ions Ca2+, Mg2+, Cu2+ and Zn2+ in the ischemia-reperfusion affected spinal cord tissues in rabbits.

To test the effects of ketamine on metal ion balance in the spinal cord tissues after ischemic reperfusion (I/R), 24 white adult Japanese rabbits were randomly assigned to sham operation group, I/R group or ketamine-treated I/R group. Spinal cord injuries in I/R group and ketamine-treated I/R group were induced by aortic occlusions. Rabbits in ketamine-treated I/R group were intravenously infused 10 mg/kg ketamine twice: once at 10 min before aortic clamping and once at the onset of reperfusion. Post-operative neurological functions and concentrations of ions Ca2+, Mg2+, Cu2+ and Zn2+ in the spinal cord were assessed. Compared with the sham operation group, rabbits in the I/R group showed significantly worsened neurological functions as scored with the modified Tarlov criteria and altered concentrations of ions Ca2+, Mg2+, Cu2+ and Zn2+. These unfavorable changes were significantly reversed in the ketamine-treated I/R group, suggesting that the potent protective effects of ketamine against the I/R-induced spinal cord injuries may be due to its ability to maintain ion balance in the I/R affected tissues.