Changes of physiological pain threshold in gonadectomized rats / 第二军医大学学报

ABSTRACT

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 mate 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.