• The Korean Journal of Physiology and Pharmacology
• /
• v.9 no.4
• /
• pp.223-230
• /
• 2005

The purpose of the present study was to examine the effect of naltrexone, an opioid antagonist, on secretion of catecholamines (CA) evoked by cholinergic nicotinic stimulation and membrane-depolarization from the isolated perfused rat adrenal gland and to establish the mechanism of its action. Naltrexone $(3{\times}10^{-6}M)$ perfused into an adrenal vein for 60 min produced time-dependent inhibition in CA secretory responses evoked by ACh $(5.32{\times}10^{-3}M)$ , high $K^+$ $(5.6{\times}10^{-2}M)$ , DMPP ($10^{-4}$ M) and McN-A-343 $(10^{-4}M)$ . Naltrexone itself did also fail to affect basal CA output. In adrenal glands loaded with naltrexone $(3{\times}10^{-6}M)$ , the CA secretory responses evoked by Bay-K-8644, an activator of L-type $Ca^{2+}$ channels and cyclopiazonic acid, an inhibitor of cytoplasmic $Ca^{2+}-ATPase$, were also inhibited. However, in the presence of met-enkephalin $(5{\times}10^{-6}M)$ , a well-known opioid agonist, the CA secretory responses evoked by ACh, high $K^+$, DMPP, McN-A-343, Bay-K-8644 and cyclopiazonic acid were also significantly inhibited. Collectively, these experimental results demonstrate that naltrexone inhibits greatly CA secretion evoked by stimulation of cholinergic (both nicotinic and muscarinic) receptors as well as that by membrane depolarization. It seems that this inhibitory effect of naltrexone does not involve opioid receptors, but might be mediated by blocking both the calcium influx into the rat adrenal medullary chromaffin cells and the uptake of $Ca^{2+}$ into the cytoplasmic calcium store, which are at least partly relevant to the direct interaction with the nicotinic receptor itself.

• Archives of Pharmacal Research
• /
• v.28 no.6
• /
• pp.699-708
• /
• 2005

The present study was designed to investigate the effect of naloxone, a well known opioid antagonist, on the secretion of catecholamines (CA) evoked by cholinergic stimulation and membrane-depolarization in the isolated perfused rat adrenal glands, and to establish its mechanism of action. Naloxone ($10^{-6}\~10^{-5}$ M), perfused into an adrenal vein for 60 min, produced dose- and time-dependent inhibition of CA secretory responses evoked by ACh ($5.32\times10^{-3}$ M), high K+ ($5.6\times10^{-2}$ M), DMPP ($10^{-4}$ M) and McN-A-343 ($10^{-4}$ M). Naloxone itself also failed to affect the basal CA output. In adrenal glands loaded with naloxone ($3\times10^{-6}$ M), the CA secretory responses evoked by Bay-K-8644, an activator of L-type $Ca^{2+}$ channels, and cyclopiazonic acid, an inhibitor of cytoplasmic $Ca^{2+}$-ATPase, were also inhibited. In the presence of met-enkephalin ($5\times10^{-6}$ M), a well known opioid agonist, the CA secretory responses evoked by ACh, high $K^+$, DMPP, McN-A-343, Bay-K-8644 and cyclopiazonic acid were also significantly inhibited. Taken together, these results suggest that naloxone greatly inhibits the CA secretion evoked by stimulation of cholinergic (both nicotinic and muscarinic) receptors as well as that by membrane depolarization. It seems that these inhibitory effects of naloxone does not involve opioid receptors, but might be mediated by blocking both the calcium influx into the rat adrenal medullary chromaffin cells and the uptake of $Ca^{2+}$ into the cytoplasmic calcium store, which are at least partly relevant to the direct interaction with the nicotinic receptor itself.

• BMB Reports
• /
• v.35 no.4
• /
• pp.420-427
• /
• 2002

Partial nerve injury is the main cause of neuropathic pain disorders in humans. Acupuncture has long been used to relieve pain. It is known to relieve pain by controlling the activities of the autonomic nervous system. Although the mechanism of neuropathic pain and analgesic effects of electroacupuncture (EA) have been studied in a rat model system, its detailed mechanism at the molecular level remains unclear. To identify genes that might serve as either markers or explain these distinct biological functions, a cDNA microarray analysis was used to compare the expression of 8,400 genes among three sample groups. Messenger RNAs that were pooled from the spinal nerves of 7 normal. 7 neuropathic pain, and 7 EA treatment rat models were compared. Sixty-eight genes were differentially expressed more than 2-fold in the neuropathic rat model when compared to the normal, and restored to the normal expression level after the EA treatment. These genes are involved in a number of biological processes, including the signal transduction, gene expression, and nociceptive pathways. Confirmation of the differential gene expression was performed by a dot-blot analysis. Dot-blotting results showed that the opioid receptor sigma was among those genes. This indicates that opioid-signaling events are involved in neuropathic pain and the analgesic effects of EA. The potential application of these data include the identification and characterization of signaling pathways that are involved in the EA treatment, studies on the role of the opioid receptor in neuropathic pain, and further exploration on the role of selected identified genes in animal models.

• Proceedings of the Ginseng society Conference
• /
• 1990.06a
• /
• pp.36-44
• /
• 1990

The analgesic effect of morphine was antagonized and the development of tolerance was suppressed by the modification of the neurologic function in the animals treated with ginseng saponins. The activation of the spinal descending inhibitory systems as well as the supraspinal structures by the administration of morphine was inhibited in the animals treated with ginseng saponins intracerebrally or intrathecally The development of morphine tolerance and dependence, and the abrupt expression of naloxone induced abstinence syndrome were also inhibited by ginsenoside Kbl , Rba, Rgl and Re. These results suggest that ginsenoside Kbl, Rba, Rgl and Re are the bioactive components of panax ginseng on the inhibition of the development of morphine tolerance and dependence, and the inhibition of abrupt abstinence syndrome. In addition, further research on the minor components of Panax ginseng should be investigated. A single or daily treatment with ginseng saponins did not induce any appreciable changes in the brain level of monoamines at the various time intervals and at the various day intervals, respectively The inhibitory or facilitated effects of ginseng saponins on electrically evoked contractions in guinea pig ileum (U-receptor) and mouse was definers (5·receptor) were not mediated through opioid receptors. The antagonism of a x receptor agonist, U-, iO.488H was also not mediated through opioid receptors in the animals treated with ginseng saponins, bolt mediated through serotonergic mechanisms. Ginseng saponins inhibited morphine S-dehydrogenase that catalyzed the production of morphine from morphine, and increased hepatic glutathione contents for the detoxification of morphine. This result suggests that the dual action of the above plays an important role in the inhibition of the development of morphine tolerance and dependence.

• The Korean Journal of Pharmacology
• /
• v.30 no.1
• /
• pp.11-18
• /
• 1994

Cyclic adenosine 3'5'-monophosphate (cyclic AMP) has been frequently accepted as an intracellular messenger for receptor-mediated action of opioids. In this experiment, it was designed to determine the interaction of dopaminergic and opioidergic system in the mouse striatum in normal and chronic haloperidol treated groups. Haloperidol 750ug/kg I.P. for 10 days was performed for dopamine denervation. The morphine, DAGO, DPDPE, and U5O,488H inhibited the increase of haloperidol-induced cyclic AMP content in chronic haloperidol treated mouse striatum. The inhibition of DAGO and DPDPE showed significant increase compared to normal mouse striatum. Naloxone showed antagonistic effect on the morphine and U5O,488H in chronic haloperidol treated group, and showed antagonistic effect on morphine, DAGO, DPDPE, and U5O, 488H in normal mouse striatum. These findings support that there is a functional interrelationship of dopaminergic and opioidergic pathway in the striatum. This result provides an evidence that following destruction of striatal dopaminergic neuron, there are some changes of cAMP content on the ${\mu},\;{\gamma},\;and\;{\kappa}$ opioid receptor, but the ${\kappa}$ opioid receptor still has its function.

• The Korean Journal of Pain
• /
• v.22 no.1
• /
• pp.58-64
• /
• 2009

Background: Magnesium is a noncompetitive antagonist of the N-methyl-D aspartate (NMDA) receptor. Magnesium is thought to be involved in opioid tolerance by way of inhibiting calcium entry into cells. Methods: The patients were randomly assigned to three groups according to the anesthetic regimens: Group M received magnesium sulfate and Group C received saline intravenously under remifentanil-based anesthesia. Group S received saline intravenously under sevoflurane based anesthesia in place of remifentanil. The patients in the group M received 25% magnesium sulfate 50 mg/kg in 100 ml of saline, and those patients in groups C and S received an equal volume of saline before induction of anesthesia; this was followed by 10 mg/kg/h infusion of either magnesium sulfate (group M) or an equal volume of saline (groups C and S) until the end of surgery. Pain was assessed on a visual analog scale at 1, 6, 12, 24, and 36 hours after the operation. The time to the first postoperative analgesic requirement and the cumulative analgesic consumption were evaluated in the three groups. Results: The visual analog scales for pain and the cumulative analgesic consumption were significantly greater in group C than in other groups. The time to first postoperative analgesic requirement was significantly shorter in group C than that in the other groups. There were no differences between group M and S for side effects. Conclusions: A relatively high dose and continuous remifentanil infusion is associated with clinically relevant evidence of acute opioid tolerance. NMDA-receptor antagonist, magnesium sulfate as an adjuvant analgesic prevents opioid tolerance in patients who are undergoing major abdominal surgery under high dose and continuous remifentanil infusion-based anesthesia.

• Advances in Traditional Medicine
• /
• v.6 no.3
• /
• pp.186-195
• /
• 2006

The present study was carried out to determine the involvement of opioid and non-opioid receptor and the effect of pH and enzymes on the recently reported antinociceptive activity of aqueous extract of Corchorus olitorius (AECO) leaves using the abdominal constriction test. The extract was prepared by soaking the dried powdered leaves of Corchorus (C.) olitorius in distilled water overnight, and the supernatant obtained was considered as a stock solution with 100% concentration/ strength. The extract, administered subcutaneously in the concentrations/ strength of 10, 50 and 100%, was found to show a significant concentration-independent antinociception. The 50% concentration AECO were further used to study on the above mentioned parameters. The extract exhibited: significant (P < 0.05) decreased in activity when pre-treated (s.c.) against 10 mg/kg naloxonazine, bicuculine (10 mg/kg), phenoxybenzamine (10 mg/kg), 10 mg/kg pindolol, and 5 mg/kg mecamylamme, but not 10 mg/kg naltrindole, 10 mg/kg atropine, respectively; significant (P < 0.05) decreased in activity after pre-treatment against 10% a-amylase, but not 1 % protease or 10% lipase and; significant (P < 0.05) decreased in activity after exposure to alkaline condition (pH between 9 and 13) while maintaining the activity at acidic condition, respectively. The C. olitorius leaves antinociception, which involved, at least in part, activation of $\mu-opioid,\;\alpha-and\;\beta-adrenergic$, and nicotinic receptors, was found to decrease under alkaline condition and in the presence of $\alpha-amylase$.

• Korean Journal of Biological Psychiatry
• /
• v.6 no.2
• /
• pp.193-201
• /
• 1999

This study was designed to evaluate the effects of opioid receptor agonists on the spontaneous alternation behaviour in an animal model of obsessivecompulsive disorder in rats. According to the theory that dopamine is related to the biological etiology of obsessive-compulsive disorder, the effect of the nalbuphine(opioid kappa agonist) and the tramadol(opioid mu agonist), which act as manipulating agents on the inhibition or stimulation of dopamine release, in the spontaneous alternation behaviour were evaluated. 24 hours prior to the experiment, rats were food-deprived. These rats were put into the T-maze, in which white and black goal boxes were baited with small amounts of chocolate milk. Each rat was given 2 set of 7 trials during which it was placed in the start box and allowed to choose the one of the goal boxes for each time. After identifying the stable baseline of spontaneous alternation behaviour, nonselective 5-HT agonist 5-MeODMT(1.25mg/kg/IP) disrupted spontaneous alternation. Rats were stratified into fluoxetine(10mg/kg/IP), nalbuphine(10mg/kg/IP), tramadol(46.4mg/kg/IP), and saline(0.5cc/IP) injection group with experimental drug treatment for 21 days. The effects on the 5-MeODMT(1.25mg/kg/IP) induced disruption of spontaneous alternation behaviour were checked at the next day of discontinuation of drug treatment. The results were as follows ; 1) At the day after 21 days of the drug treatment, the nalbuphine treated group and the fluoxetine treated group showed significant difference from the tramadol treated group and the saline treated group in the 5-MeODMT(1.25mg/kg/IP) induced suppression of spontaneous alternation behaviour. 2) Within each drug treatment group, the fluoxetine treated group showed significant difference between before and after the treatment of fluoxetine in the 5-MeODMT(1.25mg/kg/IP) induced suppression of spontaneous alternation behaviour. And also, the nalbuphine treated group showed significant difference between before and after the treatment of nalbuphine in the 5-MeODMT(1.25mg/kg/IP) induced suppression of spontaneous alternation behaviour. There was no difference between the baseline and after the treatment of nalbuphine in the 5-MeODMT(1.25mg/kg/IP) induced suppression of spontaneous alternation behaviour. We indentified that the opioid kappa agonist that act as dopamine release inhibitor affect the spontaneous alternation behaviour which is an animal model of obsessive-compulsive disorder in rat.

• Journal of Acupuncture Research
• /
• v.22 no.3
• /
• pp.23-35
• /
• 2005

Objective : The aim of the study is to investigate the effect of electro-acupuncture (EA) on ST36 to modulate immune reaction in BALB/c mice immunized intraperitoneally with 2,4-dinitrophenylated keyhole limpet protein(DNP-KLH). Methods : Experimental mice were divided into four groups : 1) Normal group was not performed by any operation. 2) IM(Immunized) group was immunized intraperitoneally with DNP-KLH and aluminum hydroxide without electro-acupunture stimulation. 3) IM-EA(immunized-elctro- acupuncture) group was performed by successive electro-acupuncture on the ST36 acupoint after immunization. 4) IM-NA(immunized-naloxone) group was performed by immunization and electro-acupuncture with same method, but naloxone was injected intraperitoneally 30 minutes before eletro-acupuncture to inhibit the opiate receptor in spleen. Serum total immunoglobulin I(IgE) and antigen-specific IgE was measured in each group. The expression of interferon-${\gamma}$ and interleukin-4 mRNA in spleen was researched by real-time RT-PCR Results : Serum total-IgE and antigen-specific IgE were significantly decreased only in IM-EA group. The expression of interleukin-4 in spleen cell was significantly reduced not only in IM-EA group, but also in IM-EA group. Conclusions : Above results indicate that the mechanism of immunomodulatory effect of electro-acupuncture is related to opioid system especially in B-cell immune reaction. Further research on the T-cell immunity is necessary to explain the mechanism of immunomodulatory effect of electro-acupuncture.

• Proceedings of the PSK Conference
• /
• 2002.04a
• /
• pp.110.1-110.1
• /
• 2002