去性腺大鼠外周痛阈的改变

Changes of physiological pain threshold in gonadectomized rats

目的:探讨性激素对外周痛觉的调节作用。方法:制备去卵巢、去睾丸大鼠模型,采用甩尾热痛仪和弗莱毛测痛法观察去性腺后雌性和雄性大鼠外周痛阈,并与各自假手术组作对比。结果:雌性大鼠去卵巢后体质量明显增加,子宫质量明显减轻(P<0.01);雄性大鼠去睾丸后体质量无明显变化。雌性大鼠去卵巢后后肢足底皮肤对机械性刺激的100%缩腿阈值明显降低(P<0.01),而热痛阈无明显改变。雄性大鼠去睾丸后后肢足底皮肤对机械性刺激的100%缩腿阈值和热刺激甩尾潜伏期均无明显改变。结论:雄激素水平的改变对大鼠外周痛阈无明显影响,而卵巢激素可能抑制大鼠外周机械性痛敏的形成,但对热痛阈无明显影响。

Objective：To investigate the modulatory effect of gonadal hormone on peripheral pain. Methods： Orchiectomized and ovariectomized rats models were established. Radio heater and Von-Frey hair were used to determine the peripheral mechanical and thermal pain threshold in gonadectomized rats and their corresponding sham-controls. Results： The body weight was increased and the uterus weight was decreased after ovariectomy in female rats（P〈0.01）. There was no significant change in the body weight of male rats after orchiectomization. The 100% hind paw withdrawal threshold to Von-Frey hair stimulation was decreased significantly after ovariectomization in female rats,with no significant change in the thermal pain threshold. There was no significant changes in the 100% hind paw withdrawal threshold after Von-Frey hair stimulation or thermal pain threshold after orchidectomy in male rats. Conclusion： These results suggest that changes in androgen level of male rats have no influence on the peripheral basal pain threshold,and female gonadal hormone may inhibit the peripheral pain signaling and has no effect on thermal pain threshold.