A-α-CAO induces weak analgesia with very short duration in mice and is able to antagonize the analgesic effect of morphine (Mor) up to 3—4 days after a single injection. No tendency of dependence has been observed. ...A-α-CAO induces weak analgesia with very short duration in mice and is able to antagonize the analgesic effect of morphine (Mor) up to 3—4 days after a single injection. No tendency of dependence has been observed. It acts as a partial agonist on MVD with Ke value of 9×10^(-9) mol/L. Its antagonist effect remains after several washes and its agonist effect cannot be reversed by naloxone (Nx), provided the incubation time or the concentration of the agent is sufficient. On isolated GPI, A-α-CAO is a pure agonist with IC_(50) of 5.7×10^(-10) mol/L; this agonist effect cannot be removed by washing but can be reversed by Nx. On RVD and RbVD, it has antagonist effect against β-endorphine (β-end) and US0488H, which cannot be washed out easily, and the pA_2are 7.5 and 7.6 respectively. A-α-CAO also inhibits the specific binding of ~3H-etorphine (~3H-Etor) to the P_2 fraction of the mouse brain membrane with an IC_(30) of 3.2×10^(-9) mol/L. The inhibition on the high affinity binding sites of ~3H-Etor remains 95％ even after 6 washes.展开更多
基金This work was partly supported by the National Natural Science Foundation of China. A part of the data has been presented on a China-US Neuroscience Conference sponsored by Academia Sinica and National Academy of Science, USA, June 7-11, 1986, at Shangh
文摘A-α-CAO induces weak analgesia with very short duration in mice and is able to antagonize the analgesic effect of morphine (Mor) up to 3—4 days after a single injection. No tendency of dependence has been observed. It acts as a partial agonist on MVD with Ke value of 9×10^(-9) mol/L. Its antagonist effect remains after several washes and its agonist effect cannot be reversed by naloxone (Nx), provided the incubation time or the concentration of the agent is sufficient. On isolated GPI, A-α-CAO is a pure agonist with IC_(50) of 5.7×10^(-10) mol/L; this agonist effect cannot be removed by washing but can be reversed by Nx. On RVD and RbVD, it has antagonist effect against β-endorphine (β-end) and US0488H, which cannot be washed out easily, and the pA_2are 7.5 and 7.6 respectively. A-α-CAO also inhibits the specific binding of ~3H-etorphine (~3H-Etor) to the P_2 fraction of the mouse brain membrane with an IC_(30) of 3.2×10^(-9) mol/L. The inhibition on the high affinity binding sites of ~3H-Etor remains 95％ even after 6 washes.
