中文摘要：

目的探讨孕酮对外周痛觉的调节作用。方法雌性SD大鼠分为4组,分别颈部皮下注射生理盐水、孕酮（500μg）、RU38486（孕酮受体的拮抗剂,20μg）及孕酮（500μg）＋RU38486（20μg）。采用弗莱毛测痛法分别测量大鼠给药前、给药后30 min及给药后60 min的外周痛阈。另取SD大鼠分为两组,分别在足底注射生理盐水、孕酮（25μg）,测量给药后15 min的外周痛阈,观察孕酮的局部效应。结果和对照组相比,颈部皮下注射孕酮30 min后,大鼠外周痛阈增高（P〈0.01）;60 min后,痛阈差异无统计学意义;颈部皮下注射RU38486后30 min及60 min,大鼠足底痛阈有显著性降低。颈部皮下同时注射孕酮和RU38486后30 min及60 min,大鼠外周痛阈差异无统计学意义。足底注射孕酮15 min后,大鼠外周痛阈与对照组相比明显提高。结论孕酮对大鼠外周机械痛起到抑制作用,而且这一作用可能是通过孕酮受体来完成的。

英文摘要：

Objective To investigate the modulatory effect of progesterone on peripheral pain.Methods Female SD rats were divided into four groups,namely,a vehicle group,a progesterone（500 μg） group,an RU38486（20 μg） group and a progesterone（500 μg） plus RU38486（20 μg） group.Von-Frey hair test was adopted to determine the peripheral mechanical pain thresholds at the following 3 time points： preinjection,30 min and 60 min after subcutaneous injection at the neck.Local effect of progesterone was also tested in SD rats by Von-Frey hair test 15 min after plantar injection of progesterone（25 μg）and normal saline（control）.Results The peripheral mechanical pain threshold was significantly increased 30 min after subcutaneous injection of progesterone at the neck compared with the vehicle group,but the threshold was not significantly different 60 min after injection.RU38486 injection at the neck significantly decreased the pain threshold of plantar at 30 min and 60 min after injection,and the peripheral mechanical pain threshold was not significantly altered at 30 min and 60 min after co-injection of progesterone and RU38486.RU38486 could block the pain inhibiting effect of progesterone. The peripheral mechanical pain threshold was also increased 15 min after plantar injection of progesterone compared with the control group.Conclusion Our findings suggest that progesterone can inhibit the peripheral mechanical pain,which might be mediated by progesterone receptor.