• Biomolecules & Therapeutics
• /
• v.7 no.1
• /
• pp.1-6
• /
• 1999

Effects of Panax ginseng on the morphine toxicity were studied in relation to its effects on the opioid receptor-G protein interactions. Morphine treatments (3 days) reduced the body weight increment rate and the weight of the thymus and spleen. These changes were usually recovered by the concomitant administration of ginseng total saponin (GTS) but occasionally further deteriorated. This discrepancy was studied in relation to the opioid receptor coupling to G protein, that is, the effects of morphine and GTS on the opioid receptors were studied using the antagonist-agonist competitive binding studies. When GTS recovered the morphine toxicity, morphine shifted the striatal $\delta$ receptors to slightly higher affinity state, and this was partly recovered by the GTS treatment. However, morphine did not have any effect on the affinity state of $\delta$ receptor from NG108-15 cells, suggesting that additional factors were needed for the modulation of the affinity states of $\delta$ receptor. Effects of morphine and GTS on $\mu$ receptor were complicate and variable, and we could not reach a clear conclusion. The morphine toxicity might accompany complicate biological involvements, and the modulation of the affinity states of the opioid receptors might explain a part of the effects of GTS on the morphine toxicity.

• The Korean Journal of Physiology and Pharmacology
• /
• v.4 no.4
• /
• pp.291-299
• /
• 2000

Morphine or butorphanol was continuously infused into cerebroventricle (i.c.v.) with the rate of $26\;nmol/{\mu}l/h$ for 3 days, and the withdrawal from opioid was rendered 7 hrs after the stopping of infusion. The expression of physical dependence produced by these opioids was evaluated by measuring the naloxone-precipitated withdrawal signs. The withdrawal signs produced in animals dependent on butorphanol (kappa opioid receptor agonist) were similar to those of morphine (mu opioid receptor agonist). Besides the behavioral modifications, opioid withdrawal affected G protein expression in the central nervous system. The G-protein ${\alpha}-subunit$ has been implicated in opioid tolerance and withdrawal. The effects of continuous infusion of morphine or butorphanol on the modulation of G protein ${\alpha}-subunit$ mRNA were investigated by using in situ hybridization study. In situ hybridization showed that the levels of $G\;{\alpha}s$ and $G\;{\alpha}i$ were changed during opioid withdrawal. Specifically, the level of $G\;{\alpha}s$ mRNA was decreased in the cortex and cerebellar granule layer during the morphine and butorphanol withdrawal. The level of $G\;{\alpha}i$ mRNA was decreased in the dentate gyrus and cerebellar granule layer during the morphine withdrawal. However, the level of $G\;{\alpha}i$ mRNA was significantly elevated during the butorphanol withdrawal. These results suggest that region-specific changes of G protein ${\alpha}-subunit$ mRNA were involved in the withdrawal from morphine and butorphanol.

• The Korean Journal of Pharmacology
• /
• v.30 no.3
• /
• pp.291-297
• /
• 1994

Our purpose was to gain insight into a possible modulatory role for ${\mu},\;{\delta},\;and\;{\kappa}$ opioid receptors by neuroleptics (chlorpromazine, thioridazine, haloperidol, sulpiride, and pimozide) in chronic morphine 5 mg/kg and 20 mg/kg treated mouse striatum. We attempted quantitative receptor assays using highly specific radioligands, $[^3H]\;DAGO\;([D-Ala^2,\;N-Mephe^4,\;Glycol^5]\;enkephalin)$, $[^3H]DPDPE\;([D-Pen^2,\;D-Pen^5]\;enkephalin)$ and $[^3H]\;DPN(diprenorphine)$ to measure the binding affinity in the experimental groups. The decrease of $[^3H]DAGO$ binding was potentiated by sulpiride and pimozide in the chronic morphine treatment (5 mg/kg and 20 mg/kg). The decrease of $[^3H]DPDPE$ binding was inhibited by chlorpromazine, thioridazine, haloperidol, sulpiride, and pimozide in chronic morphine treatment (5 mg/kg and 20 mg/kg). The decrease of $[^3H]\;DPN$ binding was significantly inhibited by chlorpromazine, thioridazine, sulpiride, and pimozide in chronic morphine 20 mg/kg treatment. $[^3H]\;DPN$ binding on the neuroleptics was antagonized by naloxone pretreatment in chronic morphine 20 mg/kg treatment. These findings suggest that neuroleptics influence opposing tonically active on the ${\delta},\;and\;{\kappa}$ opioid receptor compared with ${\mu}$ opioid receptor in the chronic morphine treated mouse striatum.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1995.04a
• /
• pp.100-100
• /
• 1995

Several behavioral studies have suggested that ginseng total saponin (GTS) antagonizes morphine actions. Based on these observations, we conducted biochemical studies to elucidate the cellular mechanism of GTS actions. morphine hydrochloride (10mg/kg, sc) and/or on (400mg/kg, oral ) were administered to mice for 14 consecutive days. Ligand binding studies were conducted from striatal membranes. For opioid receptors, morphine increased the affinity but decreased the maximal binding sites for $^3$H naloxone. GTS partially recovered it. In case of dopamine receptors, morphine increased affinity and maximal binding sites for 3H spiperone. and GTS partially blocked it. These results suggest that morphine affects cellular events by modulating opioid receptors and that opioid receptors interact with dopamine receptors to change the mental status. GTS could be helpful for the treatment of morphine- induced mental disorders.

• Toxicological Research
• /
• v.11 no.1
• /
• pp.63-68
• /
• 1995

N-methyl-D-aspartate(NMDA) receptor has been well known as an important mediator of several forms of neural and behavioral plasticity. But different results were reported about the effect of MK-801 or dextromethorphan on opioid dependence. The present studies examined whether NMDA receptor antagonists can alter the opioid dependence and tolerance in rodents. Naloxone precipitated withdrawal symptoms and changes of locomotor activities were observed in MK-801 or dextromethorphan pretreated morphine-dependent rats. Tail-flick assay was used for morphine analgesia and tolerance was found after 4 day's consecutive injections (10 mg/kg, s.c., twice/day) of morphine in mice. Locomotor activity was increased and the withdrawal symptoms were decreased by the pretreatment of MK-801 in morphine-dependent rats. But 0.3 mg/kg i.p. of MK-801 intensified the body weight loss and produced severe ataxia and rotation although some withdrawal signs were attenuated. Morphine induced analgesic tolerance was inhibited by the pretreatment of MK-801 and dextromethorphan. Dextromethorphan was more potent than MK-801 in inhibiting the development of the analgesic tolerance in mice. These results suggest that NMDA system may be involved in opioid withdrawal and analgesic tolerance but appropriate caution should be requested when MK-801 is used in combination with opioid because of untoward neurologic signs.

• International Journal of Oral Biology
• /
• v.34 no.3
• /
• pp.137-142
• /
• 2009

Whole-body $\gamma$-irradiation(WBI), which produces an oxidative stress, is reported to attenuate the acute antinociceptive action of morphine (a $\mu$-opioid receptor agonist), but not DPLPE (a $\delta$-opioid receptor agonist), in mice. Recently, we also reported that antinociceptive effect of morphine, but not $\beta$-endorphin (a novel $\varepsilon$-opioid receptor agonist), was attenuated by oxidative stress. These findings prompted us to investigate the effect of WBI on the antinociception of morphine and $\beta$-endorphin in mice. Mice were exposed to WBI (5 Gy) from a $^{60}Co$ gamma-source and tested 2 hours later for antinociception produced by intracerebroventricular administration of morphine or $\beta$-endorphin using the hot water tail-immersion and the writhing tests. WBI significantly attenuated the antinociception produced by morphine only in the hot water tail-immersion test, whereas the antinociception of $\beta$-endorphin was significantly potentiated by WBI in both tests. These results demonstrate a differential sensitivity of $\mu$- and $\varepsilon$-opioid receptors to WBI, and support the hypothesis that morphine and $\beta$-endorphin administered supraspinally produce antinociception by different neuronal mechanisms.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1993.04a
• /
• pp.62-62
• /
• 1993

Morphine은 강력한 진통작용으로 약효를 나타내고 있고 이와 같은 진통작용은 대체로 크게 대별하여 두 가지 기전으로 설명이 된다. 그 첫째는 수의 opioid수용체에 작용하여 척수에서 상행으로 전달되는 통각정보를 차단하는 것이며 또 다른 하나는 뇌에 존재하는 opioid수용체에 작용하여 진통작용을 발현한다고 알려져 있다. 실지로 임상에서 morphine을 실내에 주입하여 강한 진통작용을 가진바가 많이 보고되었다. 그러나, 아직 마약성 진통제가 뇌를 통하여 진통작용을 가지는 그 기전에 대해선 잘 밝혀지지 않았다. 많은 연구가 마약성 진통제가 뇌에 주입되면 뇌에 존재하는 opioid수용체에 작용하고 이 수용체를 가진 신경세포가 하향성 억제를 함으로써 척수에서 통각정보를 차단하여 진통작용을 나타냄을 시사한다. 그러나 아직도 이의 정확한 기전이 명쾌히 밝혀지지 않고 있다. 즉, 뇌실내에 morphine을 주입하면 이것이 과연 척수세포를 억제할 것인가에 대한 답이 없기 때문이다. 그와는 반대로 뇌실내 morphine주입은 척수세포에 아무런 영향을 미치지 못한다는 보고가 있다. 이에 본 실험은 뇌실에 주입된 morphine이 척수세포를 어떤 영향을 미치는가를 확인하고자 하였다.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 2003.04a
• /
• pp.21-37
• /
• 2003

1. Stimulation of dopaminergic system by morphine was abolished in ${\mu}$-opioid receptor knockout mice. 2. Dopaminergic stimulation by opioid agonists, morphine, DPDPE, and U50488, acts independently. 3. Loss of ${\mu}$-opioid receptors is more sensitive to the response of NMDA-induced convulsion and increase in the expression of mRNA for NMDA receptors.

• Journal of Ginseng Research
• /
• v.32 no.1
• /
• pp.1-7
• /
• 2008

Ginseng saponin has been shown to inhibit the development of dependence on morphine, cocaine, methamphetamine, but the antinarcotics effects of ginseng on nalbuphine remains still largely unknown. Ginseng administration attenuated the naloxone-induced jumping behavior on nalbuphine dependent mice. The development of morphine dependence was mediated through ${\mu}-opioid$ receptor, however, development of nalbuphine dependence was mediated through ${\kappa}-opioid$ receptor. However, it was found that the efficacy of analgesic antagonism of GTS was mediated through the serotonergic mechanism, not mediated through the opioid receptor. In addition, ginseng administration modulated cellular signal transduction in the brain. The increased NMDA receptor subunit (NR1, pNR1), phosphate extracellular signal regulated protein kinase (pERK), phosphate cAMP response element binding protein (pCREB) expression by nalbuphine was decreased by the administration of ginseng powder in cortex, hippocampus, striatum of rat brain. These results suggest that ginseng could be one of the targets of antinarcotic therapies to reduce the development of tolerance and dependence on nalbuphine as well as morphine.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1994.04a
• /
• pp.303-303
• /
• 1994

ICV infusion of morphine (MOR) produces strong analgesia in man and animals. The analgesic effect is thought to be mediated by the centrifugal inhibtory control, But neural mechanisms of the analgesic effect of ICV morphine are not well understood. For example, in the previous studies, ICV morphine does not inhibit nociceptive transmission in the spinal cord. On the contrary, ICV MOR often excites activity of dorsal horn neuron in the spinal cord. In the present study, we found that ICV MOR had dust actions on activity of dorsal horn neuron that it produced both inhibition and excitation of dorsal horn neurons. Since MOR exerts i Is action via three different types of opioid receptors, we further sought to investigate if there are differential effects of opioid receptor agonists on dorsal horn neurons when administered ICV.