The Effect of Intrathecal Bupivacaine with Hypothermia on Neuronal Protection against Transient Spinal Cord Ischemia in Rats / 대한마취과학회지

ABSTRACT

BACKGROUND: Local anesthetics can reduece excitotoxic neuronal injury from ischemia. We investigated neuroprotective effects of intrathecally administered bupivacaine and hypothermia in rat model of transient spinal cord ischemia. METHODS: A PE-10 intrathecal catheter was implanted into thirty six male Sprague-Dawley rats through L4-5 interlaminar space. Animals of normothermia (N) and hypothermia (H) groups were administered 15microliter of normal saline, and 15microliter of 0.5% bupivacaine for bupivacaine (B) and bupivacaine-hypothermia (BH) groups. Transient spinal cord ischemia was induced by inflation of a 2 F Fogarty catheter placed into aortic arch for 12 minutes. During ischemia, rectal temperature was maintained to 37.0+/-0.5 degrees C for N and B groups, 34.5 +/- 0.5degrees C for H and BH groups. Motor and sensory deficit score were assessed 2 and 24 hour after reperfusion. Lumbar spinal cords were harvested for histopathology, and for immunoreactivity of heat shock protein 70 (HSP70). RESULTS: The motor and sensory deficit score of N and B group was significantly higher than H group (P < 0.05) and BH group (P < 0.05). There were also significant difference in the motor and sensory deficit score between H and BH group at 24 hr (P < 0.05). Neuronal cell death and immunoreactivity of HSP70 was frequently observed in the N and B groups, but not in the H and BH groups. CONCLUSIONS: These results suggest that intrathecal bupivacaine did not provide neuroprotection during normothermic transient spinal cord ischemia in rats, but it can enhance neuroprotective effects of hypothermia.