己酮可可碱对兔缺血再灌注损伤脊髓的保护作用及机制

Protective effect of pentoxifylline against spinal cord ischemia/reperfusion injury in rabbits

目的:对己酮可可碱(PTX)在脊髓缺血再灌注损伤中神经元的保护作用及其机制进行初步探讨。方法:采用日本大耳白兔腹主动脉夹闭法建立脊髓缺血再灌注损伤动物模型,随机分为A组(假手术组,8只)、B组(对照组,20只)、C组(夹闭血管前用药组,20只)、D组(再灌注即刻用药组,20只)。于再灌注后12h、24h、48h、72h检测血TNF-α活性、组织MPO活性、免疫组化法观察并检测PECAM-1及caspase-3表达、HE染色观察神经元并计数坏死神经元、TUNEL染色观察并计数凋亡神经元、电镜观察坏死及凋亡神经元形态改变,并于再灌注后48h进行运动功能评分(改良Tarlov评分)。结果:用药组(C组及D组)改良Tarlov评分明显高于对照组(P<0.05),血TNF-α、组织MPO含量、免疫组化PECAM-1及caspase-3表达强度均明显下降,HE及TUNEL染色切片中坏死细胞及凋亡细胞均明显减少,与对照组有显著差异(P<0.05)。假手术组未见坏死及凋亡细胞。结论:己酮可可碱在脊髓缺血再灌注损伤中能够发挥抑制神经元坏死及凋亡的双重脊髓保护作用。

AIM： To investigate the protection of pentoxifyUine against spinal cord ischemia/reperfusion injury. METHODS ： Rabbits sustained spinal cord ischemia with 45 min cross - clamping of the infrarenal aorta. Groups were as follows： sham operation （n =8） ; ischemic control （n =20）, receiving only vehicle; PTX A （n =20）, receiving PTX before clamping and PTX B （n = 20）, receiving PTX at the onset of reperfusion. Rabbits were evaluated for hind - limb motor function with the Tarlov scoring system at 48 h. Serum was assayed with ELISA for TNF-α and spinal cords were harvest for MPO activity, histopathologic analysis and TUNEL staining. Immunohistochemistry was used for PECAM - 1 and caspase -3 detection, and the numbers of necrosic and apoptotic neuron were counted at 12 h, 24 h, 48 h and 72 h of reperfusion. The necrotic and apoptotic neurons were also observed with transmission electron microscope. RESULTS： Improved Tarlov scores were observed in PTX - treated rabbits as compared with ischemic control rabbits at 48 h. The signifi- cant reductions of TNF - α in serum, activity of MPO, immunoreactivity of the PECAM - 1 and caspase - 3 were found in PTX - treated rabbits. The numbers of necrosic and apoptotic neuron were higher in PTX - treated rabbits than that in the ischemic control rabbits （ P 〈 0. 05 ）. No necrosic and apoptotic neuron were found in the sham operation group. CONCLUSION： PTX induces protection against ischemia/reperfusion injury in the spinal cord, thereby preventing both necrosis and apoptosis.