Objective： To investigate the possible mechanisms in acupuncture analgesia by interaction of δ-opioid receptor with neurotransmitter transport proteins or the Na^＋-K^＋ pump. Methods： Microinjection of respective ...Objective： To investigate the possible mechanisms in acupuncture analgesia by interaction of δ-opioid receptor with neurotransmitter transport proteins or the Na^＋-K^＋ pump. Methods： Microinjection of respective heterologous cRNA into the Xenopus oocytes as a model system, and measurement of steady-state currents under two-electrode voltage clamp. Results： The co-expression of the 8-opioid receptor with GAT1, EAAC 1 or the sodium pump resulted in reducing activity of the respective transporter. Opioid receptor activation affected transporter activity in different ways： 1） GAT1 was further inhibited; 2） EAAC1 was stimulated; 3） Na^＋-K^＋ pump activity interfered with agonist sensitivity of DOR. Pump inhibition led to higher sensitivity for DPDPE. Conclusion： GABA transporter inhibition and glutamate transporter stimulation may counteract pain sensation by affecting the neurotransmitter concentration in the synaptic cleft and, therefore, may contribute synergistically to pain suppression by acupuncture. Sodium pump inhibition by endogenous ouabain may amplify these effects. These synergistic effects may be the molecular mechanism of inhibiting pain sense and/or acupuncture analgesia.展开更多
基金the Science Foundation of Shanghai Municipal Commission of Science and Technology(05DZ19745,06DZ19732,064319053,07DZ19722,07DZ19733)the National Basic Research Program of China(973 Program,2005CB523306)Shanghai Leading Academic Discipline Project(B112 and T0302)
文摘Objective： To investigate the possible mechanisms in acupuncture analgesia by interaction of δ-opioid receptor with neurotransmitter transport proteins or the Na^＋-K^＋ pump. Methods： Microinjection of respective heterologous cRNA into the Xenopus oocytes as a model system, and measurement of steady-state currents under two-electrode voltage clamp. Results： The co-expression of the 8-opioid receptor with GAT1, EAAC 1 or the sodium pump resulted in reducing activity of the respective transporter. Opioid receptor activation affected transporter activity in different ways： 1） GAT1 was further inhibited; 2） EAAC1 was stimulated; 3） Na^＋-K^＋ pump activity interfered with agonist sensitivity of DOR. Pump inhibition led to higher sensitivity for DPDPE. Conclusion： GABA transporter inhibition and glutamate transporter stimulation may counteract pain sensation by affecting the neurotransmitter concentration in the synaptic cleft and, therefore, may contribute synergistically to pain suppression by acupuncture. Sodium pump inhibition by endogenous ouabain may amplify these effects. These synergistic effects may be the molecular mechanism of inhibiting pain sense and/or acupuncture analgesia.
