中文摘要：

目的 探讨雌激素对急性疼痛的调节作用。方法①雌激素的慢性处理：A组大鼠在去卵巢术5周后行切口痛造模（16只），B组大鼠在去卵巢假手术5周后行切口痛造模（14只），采用vorl Frey法测定去卵巢前、后基础值以及切口痛术后2、4h和、3、7、10d的机械刺激缩足阈值（PWT值）。②雌激素的急性处理：C组为正常雌鼠在切口痛术后第1天鞘内注射1nmol／L雌二醇10μL（8只），D组为正常雌鼠在切口痛术后第l天鞘内注射0．9％氯化钠溶液10μL（8只）。采用vonFrey法测鞘内给药前及给药后20、60、120、180min的PWT值。结果①慢性处理：A组去卵巢后基础PWT值及术后1、3、7、10d的PWT值均显著低于B组（P值均〈0．05）。②急性处理：C组给药20和60min的PWT值显著低于给药前（P值均〈0．05），而D组给药后各时间点的PWT值与给药前的差异均无统计学意义（P值均〉0．05）。结论体内雌激素水平慢性降低的大鼠对于急性疼痛更加敏感，而对于处于急性疼痛状态的大鼠，中枢雌激素水平增加能引起短期痛阈的降低。

英文摘要：

Objective To investigate the modulatory effects of estrogen on acute pain. Methods The experiment was divided into two parts., long-term hormone treatment and short-term hormone treatment. The first part included two groups in group A the ovariectomized rats underwent paw incision surgery; in group B the sham ovariectomized rats underwent paw incision surgery, von Frey filaments were used to assess the pain behavior before surgery, 2 and 4 h, 1, 3, 7 and 10 d after surgery. The short-term hormone part included another two groups, in group C normal female rats were intrathecally injected with estrogens （ 1 nmol/L, estradiol 10μL, n = 8） one day after the paw incision surgery; in group D normal female rats were intrathecally injected with vehicle （0.9 % NaCl solution 10μL, n = 8） one day after the paw incision surgery, von Frey filaments were used to assess the mechanical allodynia before injection, 20,60,120 and 180 min after injection. Results The paw withdraw thresholds （PWTs） in the ovariectomized rats were significantly lower compared with those of the control group before surgery and 1, 3, 7, 10 days after the incision surgery （P〈0.05）. The PWTs in group C at 20 and 60 min after drug injection were significantly lower than those before drug injection （P〈0.05）. The PWTs in group D were similar at different time points （P〉0.05）. Conclusion Rats with slowly decreasing circulating estrogen are more sensitive to acute pain. For rats with acute pain, the increase of central estrogen level can induce transient decrease of pain threshold.