Objective： To explore the mechanism of electroacupuncture （EA）-induced cumulative analgesic effects on chronic pain in rats with or without ovariectomy （OVX）. Methods： A total of 110 female Wistar rats were rand...Objective： To explore the mechanism of electroacupuncture （EA）-induced cumulative analgesic effects on chronic pain in rats with or without ovariectomy （OVX）. Methods： A total of 110 female Wistar rats were randomized into normal control （n=10）, chronic constrictive injury （CCI, n=10）, CCI＋EA （n=30）, OVX＋CCI （n=30）, and OVX＋CCI＋EA （n=30） groups. Each of the latter 3 groups was further divided into 2 days （2 d）, 2 weeks （2 W） and 3 weeks （3 W） subgroups, respectively （n=10 in each subgroup）. The CCI pain model was established by ligature of the right sciatic nerve, and the memory impairment model duplicated by OVX. The paw withdrawal latency （PWL, pain threshold） of the bilateral footplates was detected by radiant heat irradiation, and the bilateral difference in PWL （PWLD） was used to evaluate changes in the pain reaction. Morris water maze test was conducted for evaluating the rats＇ learning-memory ability. EA was applied to bilateral Zusanli （ST36） and Yanglingquan （GB34） for 2 d, 2 W and 3 W, respectively. Pituitary and hypothalamic 13-endorphin （EP） and adrenocorticotrophic hormone （ACTH） contents were detected by immunoradioassay. Results： Compared with the CCI group, PWLD of the CCI＋EA-3 W group decreased significantly （P〈0.05）. Compared with the OVX＋CCI group, PWLD of the OVX＋CCI＋EA-3 W group was lowered considerably （P〈0.05）, but the value was markedly higher than its basal value and those of the normal control and CCI＋EA groups （P〈0.05）. In comparison with the sham-OVX group, the escape latency, swimming distance （SD） in the target quadrant and total SD were increased remarkably in the OVX group （P〈0.05）, while the number of target platform crossings was decreased significantly （P〈0.05）, suggesting an impairment of the OVX rats＇ learning-memory ability. In simple CCI rats, both β-EP and ACTH contents of the pituitary increased markedly （P〈0.05）, and those of the hypotha展开更多
基金Supported by the National Natural Science Foundation of China(No.30472241,No.90709031)the Major State Basic Research Development Program of China(973 Program,No. 2007CB512505)
文摘Objective： To explore the mechanism of electroacupuncture （EA）-induced cumulative analgesic effects on chronic pain in rats with or without ovariectomy （OVX）. Methods： A total of 110 female Wistar rats were randomized into normal control （n=10）, chronic constrictive injury （CCI, n=10）, CCI＋EA （n=30）, OVX＋CCI （n=30）, and OVX＋CCI＋EA （n=30） groups. Each of the latter 3 groups was further divided into 2 days （2 d）, 2 weeks （2 W） and 3 weeks （3 W） subgroups, respectively （n=10 in each subgroup）. The CCI pain model was established by ligature of the right sciatic nerve, and the memory impairment model duplicated by OVX. The paw withdrawal latency （PWL, pain threshold） of the bilateral footplates was detected by radiant heat irradiation, and the bilateral difference in PWL （PWLD） was used to evaluate changes in the pain reaction. Morris water maze test was conducted for evaluating the rats＇ learning-memory ability. EA was applied to bilateral Zusanli （ST36） and Yanglingquan （GB34） for 2 d, 2 W and 3 W, respectively. Pituitary and hypothalamic 13-endorphin （EP） and adrenocorticotrophic hormone （ACTH） contents were detected by immunoradioassay. Results： Compared with the CCI group, PWLD of the CCI＋EA-3 W group decreased significantly （P〈0.05）. Compared with the OVX＋CCI group, PWLD of the OVX＋CCI＋EA-3 W group was lowered considerably （P〈0.05）, but the value was markedly higher than its basal value and those of the normal control and CCI＋EA groups （P〈0.05）. In comparison with the sham-OVX group, the escape latency, swimming distance （SD） in the target quadrant and total SD were increased remarkably in the OVX group （P〈0.05）, while the number of target platform crossings was decreased significantly （P〈0.05）, suggesting an impairment of the OVX rats＇ learning-memory ability. In simple CCI rats, both β-EP and ACTH contents of the pituitary increased markedly （P〈0.05）, and those of the hypotha
