Hall E D, Smith S L, Oostveen J A
CNS Disease Research, Pharmacia & Upjohn, Inc., Kalamazoo, Michigan 49001, USA.
J Neurosci Res. 1996 May 1;44(3):293-9. doi: 10.1002/(SICI)1097-4547(19960501)44:3<293::AID-JNR10>3.0.CO;2-6.
The purpose of this study was to investigate the role of oxygen radical-induced lipid peroxidative mechanisms in trophic deprivation-induced apoptotic motor neuronal degeneration by testing the ability of the 21-aminosteroid lipid peroxidation inhibitor tirilazad mesylate (U-74006F) to attenuate the retrograde degeneration of facial motor neurons following axotomy in 14-day-old rat pups. On day 0, the right facial nerve of each rat was transected at its point of exit from the stylomastoid foramen. Pups were treated orally with either 10 or 30 mg/kg U-74006F or cyclodextrin vehicle 10 min before axotomy, and post-treated once a day from days 1 to 6, and then once every other day from days 8 to 21. The rats were sacrificed 3 weeks post-transection and the surviving motor neurons, identified through choline acetyltransferase immunocytochemistry, were counted in three regions (planes) in the facial nucleus. In vehicle-treated rats, 56.2% (region A), 50.6% (region B), and 57.4% (region C) of the motor neurons in the ipsilateral facial nucleus survived 21 days following facial nerve axotomy in comparison to the non-axotomized contralateral nucleus (P < 0.0001). Treatment with 10 mg/kg U-74006F significantly enhanced motor neuron survival in regions B and C to 72.8% (P < 0.01) and 66.7% (P < 0.02%), respectively. The 30 mg/kg dose level also increased survival rates to 64.2% (P < 0.02) and 67.9% (P < 0.01), respectively. A second experiment demonstrated that oral dosing with U-74006F (30 mg/kg), when limited to the first 5 days after axotomy, also significantly blunted retrograde degeneration measured at 21 days post-axotomy. The efficacy of the lipid peroxidation inhibitor U-74006F in protecting a portion of the facial motor neuron pool from post-axotomy degeneration suggests that lipid peroxidation may play a mechanistic role in trophic deprivation-induced apoptotic neuronal death.
本研究的目的是通过测试21-氨基类固醇脂质过氧化抑制剂甲磺酰替拉扎德（U-74006F）减轻14日龄幼鼠面神经切断后面神经运动神经元逆行性变性的能力，来研究氧自由基诱导的脂质过氧化机制在营养剥夺诱导的凋亡性运动神经元变性中的作用。在第0天，将每只大鼠的右侧面神经在其从茎乳孔穿出的部位切断。在面神经切断前10分钟，幼鼠口服10或30mg/kg U-74006F或环糊精载体，术后第1至6天每天治疗一次，然后在第8至21天每隔一天治疗一次。在横断后3周处死大鼠，通过胆碱乙酰转移酶免疫细胞化学鉴定存活的运动神经元，并在面神经核的三个区域（平面）进行计数。在给予载体的大鼠中，与未切断面神经的对侧核相比，面神经切断后21天，同侧面神经核中56.2%（区域A）、50.6%（区域B）和57.4%（区域C）的运动神经元存活（P<0.0001）。用10mg/kg U-74006F治疗可使区域B和C中的运动神经元存活率显著提高至72.8%（P<0.01）和66.7%（P<0.02%）。30mg/kg剂量水平也分别将存活率提高至64.2%（P<0.02）和67.9%（P<0.01）。第二项实验表明，当仅限于面神经切断后的前5天口服给予U-74006F（30mg/kg）时，在面神经切断后21天测量的逆行性变性也显著减弱。脂质过氧化抑制剂U-74006F在保护一部分面神经运动神经元池免于切断后变性方面的有效性表明，脂质过氧化可能在营养剥夺诱导的凋亡性神经元死亡中起机制性作用。
