雌激素对大鼠红核神经元保护作用的体视学定量

目的 观察雌激素（E₂）替代治疗对去卵巢SD大鼠脊髓损伤后红核神经元逆行性损伤的影响。方法 成年雌性SD大鼠80只, 随机分为正常组、红核脊髓束(RST)损伤组、E2替代治疗组、雌激素受体拮抗剂（ICI）治疗组和E₂+ICI联合治疗组。SD大鼠去势后1周采用选择性切断脊髓C3～C4左侧背外侧索制作单侧红核脊髓束（RST）横断损伤模型，给予不同条件治疗后1周、2周和4周对各组大鼠采用前肢支撑探测实验进行行为学评价，用红色荧光金（FR）逆行荧光示踪及体视学定量分析法，观察红核神经元的形态及数目变化。结果 前肢支撑探测实验结果显示，各时间点E2替代治疗组的左前肢使用率均高于除正常组外其他各组，但无统计学意义（P >0.05）；形态学检测结果可见各组大鼠中脑右侧FR阳性红核神经元数目除正常组外均有不同程度减少，尤以4周时最为明显。E2替代治疗组右侧中脑FR阳性红核神经元与RST损伤组、ICI治疗组和E₂+ICI 联合治疗组相比胞体饱满、轮廓清晰、突起长，体视框计数结果显示，E₂替代治疗组红核FR阳性神经元数目明显多于其余各组（P<0.05），但RST损伤组、ICI治疗组和E₂+ICI联合治疗组之间右侧中脑FR阳性红核神经元数目未见明显差异（P>0.05）。结论 大鼠脊髓横断损伤后中脑红核神经元发生逆行性损伤，E₂替代治疗可减轻脊髓损伤引发的继发性红核神经元损伤。

Neural protective effect of estrogen on the rat red nucleus by dissector quantitative analysis

Objective To investigate the protective effect of estrogen(E₂) on red nucleus after spinal cord injury (SCI) inthe ovarectomized rat. Methods Eighty adult female rats were selected in this experiment and randomly divided into the normal group, rubrospinal tract injury group, estrogen replacement group, inhibitor of estrogen receptor (ICI) treatment group and E2+ICI cooperative treatment group. Sole rubrospinal tract injury model was established by cutting off the left dorsolateral funiculus at C3-C4 segment of rat spinal cord on one week after ovariectomy operation. The animal behavior was evaluated with forelimb probing experiment, and FR positive neurons were counted and analyzed on 1 week, 2 weeks and 4 weeks by using disecter after different treatments on animals. Results The forelimb probing test showed a higher use rate of left forelimb in the E₂ replacement treatment group than that of other groups, but with no statistical significance (P>0.05). Except the normal group, the number of neurons in right red nucleus of rat midbrain decreased, especially on 4 weeks. The FR positive neurons of E₂ replacement group had a more remarkable cell body, clearer outline and longer processes compared to the neurons in the RST injury group, ICI treatment group and E2+ICI cooperative treatment group. The stereological frame illustrated that more FR positive neurons survived in the E₂ replacement group (P<0.05), but with no significant changes (P>0.05) among the RST injury group, ICI treatment group and E₂+ICI cooperative treatment group. Conclusion The E₂ replacement treatment may release red nucleus neuron retrograde injury and promote the neuron survival after rat SCI.