Delayed preconditioning effect of isoflurane on spinal cord ischemia in rats.

Paraplegia is one of the most common complications following aortic aneurysmal surgery. This study was designed to determine if isoflurane-induced delayed preconditioning is mediated by nuclear factor kappaB (NF-kappaB) in the rat spinal cord. The animals were divided into four groups: the control group, the pyrrolidinedithio carbamate (PDTC, an NF-kappaB inhibitor)-treated group, the isoflurane-treated group, and the PDTC/isoflurane-treated group. In the PDTC-treated groups, 2% 100mg/kg PDTC was administered intraperitoneally at 1h before operation and at 24h and 48 h after reperfusion. The rats in the isoflurane-treated groups received 30 min inhalation of 2.8% isoflurane at 24h before spinal cord ischemia. Pretreatment with NF-kappaB inhibitor significantly reduced NF-kappaB expression and the number of intact motor neurons when compared to the control group. Preconditioning with isoflurane increased the number of normal motor neurons, whereas pretreatment with both PDTC and isoflurane significantly decreased them, compared to the isoflurane-treated group. Isoflurane-induced delayed preconditioning on spinal cord ischemia improved histopathological outcomes. This neuroprotective effect of isoflurane preconditioning on spinal cord ischemia is associated with NF-kappaB expression.