Collaborative Therapy with Nebivalol and l-NAME for Spinal Cord Ischemia/Reperfusion Injury

Postoperative neurologic deficit is the most devastating complication after thoracoabdominal aortic aneurysm repair. Our aim was to investigate whether nebivolol has protective effects during ischemia or reperfusion and the most effective mechanism of protection via inhibiting nitric oxide (NO) release with an NO synthase inhibitor in an experimental model of spinal cord ischemia/reperfusion injury. Spinal cord ischemia was induced by occlusion of the infrarenal aorta for 30 min. Thirty-one rabbits were divided into five groups according to the administration period of nebivolol and/or N G -nitro- l -arginine methyl ester ( l -NAME): control group; group NI, nebivolol during ischemic period; group NR, nebivolol during reperfusion period; group NILR, nebivolol during ischemic period and l -NAME during reperfusion period; and group LINR, l -NAME during ischemic period and nebivolol during reperfusion period. Blood samples were taken at both ischemia and reperfusion periods to obtain nitrite/nitrate levels. After neurologic evaluation at 24 hr of reperfusion, malondialdehyde (MDA) levels were measured. Neurologic impairment was significantly lower in group LINR (Tarlov score 3.4 ± 0.6, p p p l -NAME provided the best clinical improvement by attenuating the inflammatory mileu in this experimental model. Combination of nebivolol and l -NAME appears to be an effective option for spinal cord protection against ischemia/reperfusion injury.