• Journal of Acupuncture Research
• /
• v.23 no.4
• /
• pp.149-162
• /
• 2006

Objectives : The aim of this study is to evaluate the analgesic effect of electroacupuncture on Jogsamni (ST36) in the collagen-induced arthritis rats and investigate the role played by opioid receptor subtypes $({\mu},\;{\delta},\;{\kappa})$ in the antinociceptive effect of electroacupuncture (EA) In the thermal hyper algesia test. Methods : Immunization of male Sprague-Dawley rats with bovine type H collagen emulsified in incomplete Freund's adjuvant, followed by booster injection 2 weeks later induced collagen-induced arthritis (CIA). The thermal hyperalgesia was evaluated weekly with tail flick latency (TFL). In the fourth week after first immunization, EA stimulation (2 Hz, 0.07 mA, 0.3 ms) was delivered into Jogsamni (5736) for 20 minutes. Analgesic effect was evaluated by using the tail flick latency (TFL) after intraperitoneal injection of normal saline, naloxone, naltrindole and nor-binaltorphimine respectively to CIA rats. Results : The results were as follows; 1. The TFL were gradually decreased in CIA as time elapsed after e immunization of arthrogenic collagen and the maximum value was reached between the third to fifth week. 2. EA stimulation on 5736 inhibited chronic inflammatory pain induced by CIA. 3. The analgesic effect of EA was inhibited by pretreatment of ${\mu}-receptor$ antagonist (naloxone),${\delta}-receptor$ antagonist (naltrindole) and ${\kappa}-receptor$ antagonist (nor-binaltorphimine) respectively. Conclusion : Electroacupuncture has an analgesic effect on the CIA rat and has an antinociception mediated by 8, 5, H receptors.

• Biomolecules & Therapeutics
• /
• v.18 no.3
• /
• pp.246-256
• /
• 2010

Atopic dermatitis is a common skin disease affecting up to 10% of children and approximately 2% of adults. Atopic dermatitis exhibits four major symptoms, including intense itching, dry skin, redness and exudation. The "itch-scratch-itch" cycle is one of the major features in atopic dermatitis. The pathophysiology and neurobiology of pruritus is unclear. Currently there are no single and universally effective pharmacological antipruritic drugs for treatment of atopic dermatitis. Thus, controlling of itch is a very important unmet need in patients suffering from atopic dermatitis. This article will update progress during the past 10 years of research in the field of pruritus of atopic dermatitis, focusing on aspects of pruritogens (including inflammatory lipids, histamine, serotonin, proteinases, proteinase-activating receptors, neurotransmitters, neuropeptides, and opioid peptides), antipruritic therapies, and emerging new targets. Based on recent progress, researchers expect to identify exciting possibilities for improved treatments and to develop new antipruritic drugs acting through novel targets, such as histamine H4 receptor, gastrin-releasing peptide receptor, MrgprA3, thromboxane A2 receptor and the putative SPC receptor.

• The Korean Journal of Pain
• /
• v.11 no.2
• /
• pp.294-298
• /
• 1998

The feature of neuropathic pain may occur in the absence of any apparent stimulus and be exaggerated in either amplitude or duration. Peripheral nerve injury may produce neuropathic pain and opioids have been shown to be relatively unsatisfactory for the treatment of most cases of neuropathic pain. The NMDA receptor system is involved in transmission and modulation of nociceptive information. We treated patients with severe pain, hyperaesthesia and allodynia with epidural injection of NMDA receptor antagonist, ketamine (10 mg) and morphine (0.5 mg) or other opioid. The combinations provided effective pain management in 23 patients with neuropathic pain.

• Journal of Integrative Natural Science
• /
• v.9 no.3
• /
• pp.185-189
• /
• 2016

Urotensin-2 receptor (UTS2R) is the most potent vasoconstrictor and plays a major role in the pathophysiology of various cardiovascular diseases and becomes a potential target for human pharmacotherapy. The crystal structure of Urotension-2 receptor has not yet been resolved. Hence, in the current study homology modelling of UTS2R was done utilizing the crystal structure of human delta opioid receptor as the template. Since the template has low sequence identity, we have incorporated both comparative modelling and threading approach to generate the three dimensional structure. 10 models were generated and validated. The reported models can be used to characterize the critical amino acid residues in the binding site of UTS2R.

• Korean Journal of Pharmacognosy
• /
• v.50 no.4
• /
• pp.272-276
• /
• 2019

Corylopsis gotoana has been widely used as a traditional medicine for the treatment of lots of disease including cold, edema and vomiting. However pharmacological and phytochemical studies on the C. gotoana are extremely limited. Here in this study, the author investigated the anti-nociceptive effects of the methanolic extract of Corylopsis gotoana (MCG) using various pain models. In the present study, MCG exhibited strong and dose-dependent anti-nociceptive activities on various experimental pain models including thermal nociception and chemical nociception, compared to positive control such as tramadol and indomethacin. In addition, the result from combination test using naloxone, analgesic activity of MCG was slightly reduced, indicating that MCG acts as a partial opioid receptor agonist. These results demonstrated that MCG has potent analgesic potential and thus it may be possibly used as a valuable anti-nociceptive agent.

• The Korean Journal of Pharmacology
• /
• v.25 no.1
• /
• pp.23-30
• /
• 1989

Buprenorphine, one of the mixed agonist-antagonist opioid drugs was used to inverstigate the opioid receptor on frog sciatic nerve A fibers. Action potentials were recorded for 4 hrs by a sucrose gap apparatus which were separated by four rubber membranes. To examine the one of the mechanism of action of buprenorphine, meperidine or naloxone was added after or before the treatment of buprenorphine. The results of this experiment were as follows: 1. Buprenorphine suppressed significantly the compound action potentials of frog sciatic nerve, and the maximal effects were shown both at $10^{-4}\;M$ and at $10^{-8}\;M$. 2. The dose-response relationship of buprenorphine on the depressant effect in frog sciatic nerve was biphasic and inverted U-shaped. 3. Buprenorphine blocked the effect of Meperidine $(10^{-3}\;M)$ on this preparation. 4. The depressant effcct of Buprenorphine on frog sciatic nerve was blocked by $10^{-8}\;M$ naloxone. From the above results, buprenorphine acts as one of agoinist-antagonistic effect on frog sciatic nerve, and the opioid receptor on this preparation is located on or near the intracellular opening of the sodium channels, which are sensitive to naloxone.

• The Korean Journal of Physiology and Pharmacology
• /
• v.22 no.4
• /
• pp.419-425
• /
• 2018

The superficial dorsal horn of the spinal cord plays an important role in pain transmission and opioid activity. Several studies have demonstrated that opioids modulate pain transmission, and the activation of ${\mu}$-opioid receptors (MORs) by opioids contributes to analgesic effects in the spinal cord. However, the effect of the activation of MORs on GABAergic interneurons and the contribution to the analgesic effect are much less clear. In this study, using transgenic mice, which allow the identification of GABAergic interneurons, we investigated how the activation of MORs affects the excitability of GABAergic interneurons and synaptic transmission between primary nociceptive afferent and GABAergic interneurons. We found that a selective ${\mu}$-opioid agonist, [$D-Ala^2$, $NMe-Phe^4$, Gly-ol]-enkephanlin (DAMGO), induced an outward current mediated by $K^+$ channels in GABAergic interneurons. In addition, DAMGO reduced the amplitude of evoked excitatory postsynaptic currents (EPSCs) of GABAergic interneurons which receive monosynaptic inputs from primary nociceptive C fibers. Taken together, we found that DAMGO reduced the excitability of GABAergic interneurons and synaptic transmission between primary nociceptive C fibers and GABAergic interneurons. These results suggest one possibility that suppression of GABAergic interneurons by DMAGO may reduce the inhibition on secondary GABAergic interneurons, which increase the inhibition of the secondary GABAergic interneurons to excitatory neurons in the spinal dorsal horn. In this circumstance, the sum of excitation of the entire spinal network will control the pain transmission.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.8
• /
• pp.5336-5342
• /
• 2015

Although demand for scar treatment has been rising as our quality of life is improved, most scar treatment products rely on importation. Enkephalin is one of the neuropeptides secreted from neuronal ends. As both skin and neuron are derived from the exoderm during the development process, skin cells express opioid receptors as neuronal cells do. Opioid receptors are categorized into three types, mu(m)-, delta(d)-, and kappa(k)- opioid receptors, all of which are directly involved in the wound healing process. In this study, enkephalin derivatives are synthesized by Alanin Scan and their efficacy was evaluated and compared. In vitro wound healing effects, stimulatory effects of collagen synthesis, and skin hydration effects were also evaluated and confirmed. Among Enkephalin derivatives, AS13 showed highest wound healing effect.

• The Korean Journal of Pain
• /
• v.20 no.2
• /
• pp.100-105
• /
• 2007

Background: Ginseng has been used to manage various types of pain in folk medicine. This study characterized the effect of treatment with intrathecal ginsenosides, the active components of ginseng in a postoperative pain model. Methods: Male Sprague-Dawley rats were implanted with lumbar intrathecal catheters. An incision was made in the plantar surface of the hindpaw. Withdrawal thresholds following the application of a von Frey filament to the wound site were measured. To determine the role of the opioid or GABA receptors following treatment with the ginsenosides, naloxone, bicuculline (a $GABA_A$ receptor antagonist), and saclofen (a $GABA_B$ receptor antagonist) were administered intrathecally 10 min before the delivery of the ginsenosides and the changes of the withdrawal thresholds after application of the von Frey filament were Observed. Results: Treatment with the intrathecal ginsenosides increased the withdrawal threshold in a dose dependent manner. Pre-treatment with intrathecal naloxone reversed the antinociceptive effect of the ginsenosides. However, pre-treatment with intrathecal bicuculline and saclofen failed to have an effect on the activity of the ginsenosides. Conclusions: These results suggest that ginsenosides are effective to alleviate the postoperative pain evoked by paw incision. The opioid receptor, but not GABA receptors, may be involved in the antinociceptive action of the ginsenosides at the spinal level.

• Journal of Ginseng Research
• /
• v.26 no.4
• /
• pp.187-190
• /
• 2002

Crude synaptic membrane fractions from the frontal cortex, striatum, brain stem and whole brain of rat were prepared to assay the effects of ginseng total saponin (GTS) on [$^3$H]DAGO bindings of the opioid $\mu$-receptors. Scatchard plots analysis binding data demonstrated that GTS (0.1 mg/ml) decreased the affinity of specific [$^3$H]DAGO bindings without changes in B$\_$max/ in the frontal cortex and striatum. On the other hand, GTS did not affect the [$^3$H]DAGO bindings iii the brain stem and whole brain. These results suggest that the regulation of [$^3$H]DAGO bindings by GTS may play roles in the change of the pharmacological responses of $\mu$-opioids.