Chemical modification of receptor molecules has become an important method for studying the structure and function of receptors. Dithiothreitol (DTT) is a common agent used for protecting sulfhydryl groups as well as ...Chemical modification of receptor molecules has become an important method for studying the structure and function of receptors. Dithiothreitol (DTT) is a common agent used for protecting sulfhydryl groups as well as reducing the disulfide bonds. Larsen et al. (1981) used DTT (10 mmol/L) to protect opioid展开更多
Since the demonstration of opioid receptors in the brain in 1973 and the discovery of endogenous opioid peptides in 1975, the study of opioid receptors becomes one of the most important frontier purports in neural sci...Since the demonstration of opioid receptors in the brain in 1973 and the discovery of endogenous opioid peptides in 1975, the study of opioid receptors becomes one of the most important frontier purports in neural science. Many scientists have engaged in the isolation and purification of the receptor protein. Cho et al. (1986)展开更多
Ⅰ. INTRODUCTION In 1974, Collier et al. reported that morphine and its congeners inhibited the activity of adenylate cyclase （AC） of rat brain homogenates, stimulated by prostaglandins E1 （PGE1） and E, （PGE2）, ...Ⅰ. INTRODUCTION In 1974, Collier et al. reported that morphine and its congeners inhibited the activity of adenylate cyclase （AC） of rat brain homogenates, stimulated by prostaglandins E1 （PGE1） and E, （PGE2）, and that the inhibition was mediated by opiate receptors. Sharma et al. also demonstrated that morphine and a series of opiates could inhibit this enzyme in neuroblastoma×glioma hybrid cells stimulated by PGE1,展开更多
The multiplicity of opiate receptors has turned out to be the most attractive to workers in this field, since Martin et al. (1976) pointed out the possible existence of more than one subtypes Of opiate receptors. Rat ...The multiplicity of opiate receptors has turned out to be the most attractive to workers in this field, since Martin et al. (1976) pointed out the possible existence of more than one subtypes Of opiate receptors. Rat vas deferens (RVD) is a commonly used preparation for pharmacological studies in vitro, but reports on the effect of opiates on RVD are rather contradictory. Hughes et al. (1975) found that morphine did not展开更多
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
文摘Chemical modification of receptor molecules has become an important method for studying the structure and function of receptors. Dithiothreitol (DTT) is a common agent used for protecting sulfhydryl groups as well as reducing the disulfide bonds. Larsen et al. (1981) used DTT (10 mmol/L) to protect opioid
文摘Since the demonstration of opioid receptors in the brain in 1973 and the discovery of endogenous opioid peptides in 1975, the study of opioid receptors becomes one of the most important frontier purports in neural science. Many scientists have engaged in the isolation and purification of the receptor protein. Cho et al. (1986)
文摘Ⅰ. INTRODUCTION In 1974, Collier et al. reported that morphine and its congeners inhibited the activity of adenylate cyclase （AC） of rat brain homogenates, stimulated by prostaglandins E1 （PGE1） and E, （PGE2）, and that the inhibition was mediated by opiate receptors. Sharma et al. also demonstrated that morphine and a series of opiates could inhibit this enzyme in neuroblastoma×glioma hybrid cells stimulated by PGE1,
文摘The multiplicity of opiate receptors has turned out to be the most attractive to workers in this field, since Martin et al. (1976) pointed out the possible existence of more than one subtypes Of opiate receptors. Rat vas deferens (RVD) is a commonly used preparation for pharmacological studies in vitro, but reports on the effect of opiates on RVD are rather contradictory. Hughes et al. (1975) found that morphine did not
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.
