In our previous work, acupuncture induced inhibition of the nociceptive respons e to peripheral noxious stimulation at spinal level could be blocked by iontopho retic bicuculline(Bic), an antagonist for GABA A recepto...In our previous work, acupuncture induced inhibition of the nociceptive respons e to peripheral noxious stimulation at spinal level could be blocked by iontopho retic bicuculline(Bic), an antagonist for GABA A receptors, suggesting an invol vement of GABA in acupuncture induced segmental inhibition. However some report s declare that increase in GABA content in brain is not benefit to acupuncture ana lgesia. In this paper, the effects of intra cerebroventricular and intrathecal i njection (icv and ith) of Bic on acupuncture analgesia were further investigated by tail flick latency tests in rats. There were 6～8 rats in each group. Th e results were as follows: 1. After icv GABA in dose of 0, 125, 250, 500 and 1000 μg /5 μL, the pain thre shold (PT) were raised to 102%, 108%, 128%, 136%, and 157% of the basal control value respectively. It indic ates that icv GABA could produce dose dependent analgesic effect. 2. After icv Bic at the dose of 10 and 20 μg /5 μL, icv GABA (500 μg /5 μL) induced analgesic effect lowered from 136.24±1.96% to 111.8±0.98% and 111.25±0.65% separately. It means that icv GABA induced analgesic effect is significantly blocked by preinjection of Bic. 3. After electro acupuncture at bilateral "Ciliao" (BL 32) points (50 Hz, 1～2 mA) for 10 minutes, PT were raised to 142.50±2.10% without any treatment and 1 4 3.72±2.04% with pretreatment of saline. When pretreated with icv Bic at doses o f 10 and 20 μg /5 μL, acupuncture analgesic effects (PT still raised to 141.74 ±1.54% and 146.71±1.85%) showed no significant reduction. It indicates tha t GABA in brain might not be involved in acupuncture analgesia. 4. After electro acupuncture at bilateral "Ciliao"(BL 32), PT were raised to 139.56±1.21% with ith saline and to 138.96±1.43% pretreated with ith Bic 5 μg /10 μL. When pretreated with ith Bic at doses of 10 and 20 μg /10 μL, PT wer e raised to 126.55±1.73% and 114.52±1.68% respectively, indicating the signifi cant reduction of acupuncture analgesia. It means that GABA might be involved in acu puncture analgesia mediated by activation of A receptors at spinal level.展开更多
In our previous work, acupuncture induced elevation of pain threshold could not be blocked by intra cerebroventricular injection of bicuculline, an antagonist f or GABA A receptors, suggesting that GABA in brain might...In our previous work, acupuncture induced elevation of pain threshold could not be blocked by intra cerebroventricular injection of bicuculline, an antagonist f or GABA A receptors, suggesting that GABA in brain might not be involved in acup uncture analgesia, at least might not be mediated by activation of GABA A recept ors. In this paper, the effects of intra cerebroventricular and intrathecal inj e ction (icv and ith) of CGP 55845, a potent and selective antagonist against GABA B receptor, on acupuncture analgesia were further investigated by tail flick la tency tests in rats. There were 6～8 rats in each group. The results were as f ollows: 1. After icv and ith baclofen(Bac), an agonist of GABA B receptor at doses of 0. 0 25 μg /5 μL and 0.25 μg /10 μL(+5 μL saline) , pain threshold (PT) were rai sed to 125.11±1.94% and 128.63± 0.93% of the basal control value respective ly. While subcutaneous injection of Bac, 50 μg /kg was needed to produce significant analgesic effect (PT raised to 130.94±1.62%). It indicates that activation of GABA B receptor co uld produce analgesic effects mainly in the central nervous system. 2. After icv CGP 55845 at doses of 0.5, 5.0, and 50 ng /5 μL, icv Bac (2.5 μg /5 μL) induced analgesic effect (PT raised to 136.24±1.96%) was blocked by 3 7.4%, 77.0% and 75.1% respectively (PT raised to 130.43±1.72%, 111.8±0.98% and 111.25±0.65%). It means that icv Bac induced analgesic effect could be signif icantly blocked by pretreatment of icv CGP 55845. 3. After electroacupuncture at bilateral "Ciliao"(BL 32) points (50 Hz, 1～2 mA) for 10 minutes, PT were raised to 142.50±2.10 % without treatment, 143.74±2.0 4% with pretreatment of saline and 142.47±1.18% with pre icv CGP 55845 at dose s of 0.5 ng/5 μL. When pretreated with icv CGP 55845 at doses of 5 and 50 ng/ 5 μL, acupuncture analgesic effects were significantly blocked by 73.7% and 71. 6% (PT raised to 111.19±1.20% and 112.09±1.12%). It indicates that GABA in brai n might be involved in acupuncture analgesia mainly mediated by activation of GA BA B receptors. 4. After electroacupuncture at bilateral "Ciliao"(BL 32) points, PT were ra ised to 138.15± 1.64% with pretreatment(ith) of saline and to 138.56±1 .21% with pretreatment(ith) of CGP 55845 5 ng/5 μL. When pretreated with ith CGP 55 845 at doses of 50 and 500 ng /5 μL, PT were raised to 119.04±1.04% and 109.08 ±1.94% respectively, indicating that acupuncture analgesia could be significant ly blocked by 52.6% and 76.7%. It means that GABA might also be involved in acup uncture analgesia mediated by activation of B receptors at spinal level.展开更多
文摘In our previous work, acupuncture induced inhibition of the nociceptive respons e to peripheral noxious stimulation at spinal level could be blocked by iontopho retic bicuculline(Bic), an antagonist for GABA A receptors, suggesting an invol vement of GABA in acupuncture induced segmental inhibition. However some report s declare that increase in GABA content in brain is not benefit to acupuncture ana lgesia. In this paper, the effects of intra cerebroventricular and intrathecal i njection (icv and ith) of Bic on acupuncture analgesia were further investigated by tail flick latency tests in rats. There were 6～8 rats in each group. Th e results were as follows: 1. After icv GABA in dose of 0, 125, 250, 500 and 1000 μg /5 μL, the pain thre shold (PT) were raised to 102%, 108%, 128%, 136%, and 157% of the basal control value respectively. It indic ates that icv GABA could produce dose dependent analgesic effect. 2. After icv Bic at the dose of 10 and 20 μg /5 μL, icv GABA (500 μg /5 μL) induced analgesic effect lowered from 136.24±1.96% to 111.8±0.98% and 111.25±0.65% separately. It means that icv GABA induced analgesic effect is significantly blocked by preinjection of Bic. 3. After electro acupuncture at bilateral "Ciliao" (BL 32) points (50 Hz, 1～2 mA) for 10 minutes, PT were raised to 142.50±2.10% without any treatment and 1 4 3.72±2.04% with pretreatment of saline. When pretreated with icv Bic at doses o f 10 and 20 μg /5 μL, acupuncture analgesic effects (PT still raised to 141.74 ±1.54% and 146.71±1.85%) showed no significant reduction. It indicates tha t GABA in brain might not be involved in acupuncture analgesia. 4. After electro acupuncture at bilateral "Ciliao"(BL 32), PT were raised to 139.56±1.21% with ith saline and to 138.96±1.43% pretreated with ith Bic 5 μg /10 μL. When pretreated with ith Bic at doses of 10 and 20 μg /10 μL, PT wer e raised to 126.55±1.73% and 114.52±1.68% respectively, indicating the signifi cant reduction of acupuncture analgesia. It means that GABA might be involved in acu puncture analgesia mediated by activation of A receptors at spinal level.
文摘In our previous work, acupuncture induced elevation of pain threshold could not be blocked by intra cerebroventricular injection of bicuculline, an antagonist f or GABA A receptors, suggesting that GABA in brain might not be involved in acup uncture analgesia, at least might not be mediated by activation of GABA A recept ors. In this paper, the effects of intra cerebroventricular and intrathecal inj e ction (icv and ith) of CGP 55845, a potent and selective antagonist against GABA B receptor, on acupuncture analgesia were further investigated by tail flick la tency tests in rats. There were 6～8 rats in each group. The results were as f ollows: 1. After icv and ith baclofen(Bac), an agonist of GABA B receptor at doses of 0. 0 25 μg /5 μL and 0.25 μg /10 μL(+5 μL saline) , pain threshold (PT) were rai sed to 125.11±1.94% and 128.63± 0.93% of the basal control value respective ly. While subcutaneous injection of Bac, 50 μg /kg was needed to produce significant analgesic effect (PT raised to 130.94±1.62%). It indicates that activation of GABA B receptor co uld produce analgesic effects mainly in the central nervous system. 2. After icv CGP 55845 at doses of 0.5, 5.0, and 50 ng /5 μL, icv Bac (2.5 μg /5 μL) induced analgesic effect (PT raised to 136.24±1.96%) was blocked by 3 7.4%, 77.0% and 75.1% respectively (PT raised to 130.43±1.72%, 111.8±0.98% and 111.25±0.65%). It means that icv Bac induced analgesic effect could be signif icantly blocked by pretreatment of icv CGP 55845. 3. After electroacupuncture at bilateral "Ciliao"(BL 32) points (50 Hz, 1～2 mA) for 10 minutes, PT were raised to 142.50±2.10 % without treatment, 143.74±2.0 4% with pretreatment of saline and 142.47±1.18% with pre icv CGP 55845 at dose s of 0.5 ng/5 μL. When pretreated with icv CGP 55845 at doses of 5 and 50 ng/ 5 μL, acupuncture analgesic effects were significantly blocked by 73.7% and 71. 6% (PT raised to 111.19±1.20% and 112.09±1.12%). It indicates that GABA in brai n might be involved in acupuncture analgesia mainly mediated by activation of GA BA B receptors. 4. After electroacupuncture at bilateral "Ciliao"(BL 32) points, PT were ra ised to 138.15± 1.64% with pretreatment(ith) of saline and to 138.56±1 .21% with pretreatment(ith) of CGP 55845 5 ng/5 μL. When pretreated with ith CGP 55 845 at doses of 50 and 500 ng /5 μL, PT were raised to 119.04±1.04% and 109.08 ±1.94% respectively, indicating that acupuncture analgesia could be significant ly blocked by 52.6% and 76.7%. It means that GABA might also be involved in acup uncture analgesia mediated by activation of B receptors at spinal level.
