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Biomedical subjects

W Q Jin

Publications and source records attributed to W Q Jin.

30 records · Page 2Linked to original sources
PubMed1987

The choice of opioid receptor subtype in isolated preparations by ohmefentanyl.

Ohmefentanyl has significant inhibitory actions on the electrically evoked contractions of guinea pig ileum and mouse vas deferens. Their IC50 values are 0.15 nM and 0.89 nM, respectively. In the guinea pig ileum and the mouse vas deferens, both mu-antagonist naloxone and (mu + kappa)-antagonist Mr. 2266 antagonize readily the agonist action of ohmefentanyl, indicating that ohmefentanyl acts on mu-receptors in the guinea pig ileum and the mouse vas deferens. Like other mu-agonists, ohmefentanyl has agonist activity but no antagonist action in the rat vas deferens. In the rabbit vas deferens, the activity of ohmefentanyl is very weak. The IC50 value is 149 nM. These results further indicate that ohmefentanyl is a potent and selective mu-agonist.

Analgesics↗
PubMed1986

Electroacupuncture and morphine analgesia potentiated by bestatin and thiorphan administered to the nucleus accumbens of the rabbit.

The endogenous opioid peptide enkephalin (EK) is known to be degraded mainly by two enzymes, the dipeptidyl carboxypeptidase 'enkephalinase' and aminopeptidase. Microinjection of the enkephalinase inhibitor thiorphan or the aminopeptidase inhibitor bestatin into the nucleus accumbens of the rabbit produced a dose-dependent analgesic effect. This analgesic effect was totally reversed by the narcotic antagonist naloxone or by antibodies against [Met5]enkephalin (MEK) administered to the same site. Antibodies against [Leu5]enkephalin were not effective. Moreover, microinjection of thiorphan or bestatin into the nucleus accumbens resulted in a marked potentiation of the aftereffect of electroacupuncture (EA) produced analgesia, as well as the analgesia induced by a small dose of morphine. It is concluded that the analgesic effect elicited by EA and morphine is mediated, at least in part, by MEK-like immunoreactive substance(s) in the nucleus accumbens.

Amino Acids, Sulfur↗
PubMed1983

Interactions of some 4-anilinopiperidines and 4-phenylpiperidines with the mu, delta- and kappa-binding sites.

The binding and pharmacological profiles of some 4-anilinopiperidine and 4-phenylpiperidine analogues were determined. The potency of the compounds to displace the binding of selective tritiated ligands was measured in homogenates of guinea-pig brain at 25 degrees C. All the compounds tested had high affinity for the mu-binding site, low affinity for the delta-site and were almost inactive at the kappa-site. The compounds were also tested for agonist activity in the guinea-pig ileum and the vasa deferentia of the mouse and rat. The pharmacological and binding profiles were compared.

Animals↗
PubMed1981

Studies on synthesis and relationship between analgesic activity and receptor affinity for 3-methyl fentanyl derivatives.

In the present paper, the synthesis and analgesic activity (mice, i.p. hot plate test) of the derivatives of 3-methyl fentanyl are briefly described. Compound 7302, cis-N-[1-(2-hydroxy-2-phenylethyl)-3-methyl-4-piperidyl]-N-phenylpropionamide (cis: 3-methyl/4-N-phenylpropionamide) is found to be the most potent analgesic agent in this series synthesized by our laboratory (ED50 = 0.0022 mg/kg). The analgesic activity of 7302 is 28 times more potent than that of fentanyl and 6300 times more than that of morphine. The partition coefficients of 10 compounds in the series are determined by high performance liquid chromatography (HPLC) and their log p values are about 3. There are no regular relationships between the analgesic activity and partition coefficients. Study on the specific binding of 8 out of the above 10 compounds to crude synaptic plasma membrane (P2-fraction) of mouse brain demonstrates that there is an excellent statistical linear correlation (r = 0.998) between the analgesic potency and the specific binding affinity. The result shows that the analgesic potency of the derivatives of this series is mainly dependent on binding affinity for opiate receptor.

Analgesics↗