Effect Of Propofol On Excitatory Amino Acid Accumulation For Ischemia-Reperfusion Injury To Spinal Cord In Rabbits

Objective: To investigate the effect of propofol on excitatory amino acid accumulation for an ischemia-reperfusion spinal cord injury in rabbits.Methods: Sixty healthy adult New Zealand white rabbits were randomly divided into 6 groups, i.e., Groups A to F, with 10 rabbits in each group. Under general anesthesia, the infrarenal circumaortic clamping model was used. Normal saline, 10% intralipid, propofol 30mg/kg, propofol 40mg/kg, propofol 50mg/kg, and propofol 60mg/kg were given in Group A to Group F, respectively. Ischemia lasted for 30 min. Normal saline, 10% intralipid and propofol were continuously infused through a catheter into the aorta distal to the clamping site at a speed of 12 ml/kg/h during the ischemia period. At 0, 6, 24,and 48 h after reperfusion, neurologic outcomes were scored on a 0~4 grading scale (Tarlov scale system). The numbers of normal neurons in the anterior spinal cord were counted. Concentrations of excitatory amino acids (aspartate and glutamate) of the lumbar spinal cord were measured after 48 h of reperfusion with thehigh performance liquid chromatography. Statistical analyses were performed with PEMS 3.1 software package and SPSS 12.0 software.Results: The neurologic outcomes were better and the pathological changes were less severe in the propofol groups than in the control group and the intralipid group(P < 0.05).The differences were significant among all the propofol groups except the difference between Group C and Group F. The numbers of normal neurons in the anterior spinal cord in the propofol groups were greater than in the control group and the intralipid group(P < 0.05). Concentrations of excitatory amino acids indicated that propofol decreased excitatory amino acid accumulation in the spinal cord. This inhibitive effect isConclusions: Propofol can significantly inhibit the accumulation of EAAs in spinal cord and provide a protective effect against an ischemia-reperfusion injury to the spinal cord in rabbits. This neurological protection may be due to the acceleration of excitatory amino acid elimination in the reperfusion. The protective effect is dose-depended with propofol in a certain dose range.