• The Korean Journal of Pharmacology
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• v.20 no.2
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• pp.15-21
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• 1984

It was aimed to study the effects of ${\alpha}_2-adrenoceptor$ agonists on the sleeping time in $one{\sim}two-day-old$ chickens. Furthermore, it was also evaluated whether ${\alpha}_1-adrenoceptor$ agonist and antagonist might affect the sleeping in the chickens and discussed in relation with opiate receptor. 1) Guanabenz, clonidine, guanfacine and B-HT 933 decreased the latency of the loss of righting reflex in a dose-dependent manner, but B-HT 920 and oxymetazoline slightly prolonged it. 2) ${\alpha}_2-Adrenoceptor$ agonists produced dose·related increase in sleeping time. The potency was guanabenz>clonidine>oxymetazoline${\geq}$B-HT 933${\geq}$B-HT 920>guanfacine in this order. 3) ${\alpha}_2-Adrenoceptor$ antagonists decreased guanabenz-induced sleeping time in a dose ·dependent manner. The rank order of ${\alpha}_2-adrenoceptor$ antagonists was yohimbine>rauwolscine>piperoxan${\geq}$RX 781094. 4) Sleeping time caused by both ethanol and hexobarbital was not affected by yohimbine in chickens. 5) Methoxamine and phenylephrine showed little significant effect on the guanabenz-induced sleeping time. However, prazosin increased it. Paradoxically, corynanthine rather caused to decrease it. These results suggest that the stimulation of central ${\alpha}_2-adrenoceptor$ mediates sleeping, however it is remained uncertain in the role of central ${\alpha}_1-adrenoceptor$ in chickens. In addition, the one~two-day-old chickens may be considered as a useful, inexpensive and simple experimental model to evaluate the in vivo pharmacological action of the ${\alpha}_2-adrenoceptor$ agonist and antagonist related to sedation.

• The Korean Journal of Pharmacology
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• v.30 no.1
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• pp.11-18
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• 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 Pharmacology
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• v.17 no.2
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• pp.17-22
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• 1981

In the electrically stimulated guinea-pig ileum, which was incubated in the modified Krebs-Henseleit bicarbonate buffer solution containing various concentrations of electrolytes at $4^{\circ}C$ for 24 hours, the effect of naloxone on the inhibitory action of morphine was investigated. Incubation potentiated the inhibitory action of morphine. In the incubated preperation, the inhibitory action of morphine was potentiated in the $Na^+\;75mM$, and $K^+\;2.9mM$ groups, while that action of morphine was reduced in the $Ca^{++}\;3.6mM,\;Mg^{++}$ free and $Mn{++}\;0.2mM$ groups. Naloxone in incubation media potentiated in the inhibitory action of morphine. In the preparations which were incubated in various concentrations of electrolytes plus naloxone, the action of morphine was reduced in $Na^+\;75mM,\;K^+\;2.9mM$, and $Ca^{++}\;3.6mM$ groups, while that action of morphine was potentiated in $Mg^{++}$free and $Mn{++}\;0.2mM$ groups. Naloxone antagonised those actions of morphine. However, $pA_2$ values for naloxone (index for affinity for antagonist) was not changed. Thus changes in the inhitory action of morphine caused by incubation are probably not the result of changes in the affinity of receptor, but due to the alterations in the events which precede or follow the receptor binding by incubations.

• The Korean Journal of Pain
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• v.9 no.1
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• pp.151-158
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• 1996

Background: Buprenorphine, a new synthetic thebaine derivative, is a partial agonist of the opioid $\mu$-receptor with high receptor affinity, great lipid solubility, and slow rate of opiate receptor association and dissociation. Continuous epidural infusion of opioid can possibly produced undesirable effects, such as respiratory depression, pruritus, etc, in spite of effective postoperative analgesia. Methods: The present study was undertaken to compare the analgesic properties and side effects of continuous epidural infusion of buprenorphine combined with bupivacaine, and morphine combined with bupivacaine in 90 patients following elective gynecologic lower abdominal surgery. At the end of surgery, the initial bolus doses were 3 mg morphine (M group), 0.15 mg buprenorphine (0.15B group), 0.3 mg buprenorphine (0.3B group) combined with 0.25% bupivacaine 10ml, and subsequent continuous infusion doses were 6 mg morphine plus 0.125% bupivacine 100 ml (M group) and 0.6mg buprenorphine plus 0.125% bupivacaine 100 ml (0.15B, 0.3B, group) during 48 hours. The assessment of analgesic efficacy and side effects were made at arrival of recovery room, 1 hr, 4 hr, 8 hr, 24 hr, 36 hr, and 48 hr after the epidural injection. Results: The pain score during 48 hours was significantly higher in the 0.15B group than in the M group and 0.3B group (P<0.05), and the number of patients requiring additional analgesics was significantly higher in the 0.15B group than in the M group and 0.3B group (P<0.05). Signs of respiratory depression were not noted, and the incidence of pruritus, nausea, and vomiting was slightly lower in the 0.15B group and 0.3B group than in the M group, and the incidence of sedation and urinary retention was similar in three group. The subjective rating of satisfaction was better in the 0.3B group than in the M group and 0.15B group (P<0.05). Conclusion: The above results suggest that continuous epidural infusion of buprenorphine combined with low-dose bupivacaine is an advisable method of postoperative analgesia.

• The Korean Journal of Pain
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• v.1 no.1
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• pp.53-58
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• 1988

We have treated patients who have visited pain clinic and those admitted to the other departments of Pusan National University Hospital from Mar. 1987 to Feb. 1988 with complaints of severe cancer pain on both upper and lower abdomen and extremities by continuous administration of a very small amount of morphine in the lumbar subarachnoid(group I) and epidural(group II) space in 10 cases respectively. The results of analgesia obtained are as follows: 1. The average duration in onset of analgesia was 8 mins. in group I and 23 mins. in group II. 2. The average duration In maintaining analgesia was 12.4 hrs. in group I and 18.4 hrs. in group II. 3. The efficiency of analgesia in group I was excellent in 5, good in 4, and null in 1, and group II was excellent in 5, good in 2, and moderate in 3. 4. The degree of tolerance in group I was rather mild comparable ti that of pain score 4 till the 22nd. day of morphine administration. 5. The complications are: 2 of respiratory distress in group I, 2 of voiding difficulties in both group I and II, 1 of itching sensation in both group I and II, 1 of euphoria with hallucination In group I, and 1 of C.S.F leakage in group II. As results, it is thought that epidural administration is safer than subarachnoid administration in achieving analgesia with morphine among patients with malignant pain if the problem of tolerance is solved.

• The Korean Journal of Pain
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• v.8 no.2
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• pp.235-243
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• 1995

A retrospective study was performed to evaluate the effects, and side effects, of epidural analgesia for postoperative pain relief of 2,381 surgical patients who received general-epidural, or epidural anesthesia only. Anesthesia records, patients charts, and pain control records were reviewed and classified according to: age, sex, body weight, department, operation site, epidural puncture site, degree of pain relief by injection mode & epidural injectate, and side effects(including nausea, vomiting, pruritus, urinary retention and respiratory depression). The results were as follows: 1) From the total of 2,381 patients, there were 1,563(66%) female patients; 1.032(43%) patients were from Obstetrics and Gynecology. 2) Lower abdomen, thorax, lower extremity and upper abdomen in the operation site; and lumbar, upper, lower thoracic in puncture site were order of decreasing frequency. Length of epidural injection for pain relief averaged $1.72{\pm}1.02$ days. 3) Ninety three percent of the patients experienced mild or no pain in the postoperative course. Analgesic quality was not affected by the kind of epidural injectate. 4) Nausea occurred in 3.2% of all patients, vomiting in 1.1%, pruritus 0.9%, urinary retention 0.6%, respiratory depression 0.08%. 5) Frequency of nausea was higher with female patients compared to male patients(p<0.05). 6) Pruritus frequency was higher with male patients than female patients(p<0.05); and more frequent with patients who received epidural injection with morphine than patients who received epidural injection without morphine(p<0.01). 7) Urinary retention was higher in female patients, and more frequent with patients who had received epidural injection with morphine than epidural injection without morphine(p<0.05). 8) There were two cases of respiratory depression. The course of treatment consisted of: cessation of epidural infusion, then administration of oxygen and intravenous naloxone. We conclude that postoperative epidural analgesia with a combination of local anesthetics and opiate is and effective method for postoperative pain relief with low incidence of side effects. However, patients should be carefully evaluated as rare but severe complications of respiratory depression may ensue.

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

• Molecules and Cells
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• v.41 no.5
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• pp.454-464
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• 2018

Crosstalk between G-protein signaling and glutamatergic transmission within the brain reward circuits is critical for long-term emotional effects (depression and anxiety), cravings, and negative withdrawal symptoms associated with opioid addiction. A previous study showed that Regulator of G-protein signaling 4 (RGS4) may be implicated in opiate action in the nucleus accumbens (NAc). However, the mechanism of the NAc-specific RGS4 actions that induce the behavioral responses to opiates remains largely unknown. The present study used a short hairpin RNA (shRNA)-mediated knock-down of RGS4 in the NAc of the mouse brain to investigate the relationship between the activation of ionotropic glutamate receptors and RGS4 in the NAc during morphine reward. Additionally, the shRNA-mediated RGS4 knock-down was implemented in NAc/striatal primary-cultured neurons to investigate the role that striatal neurons have in the morphine-induced activation of ionotropic glutamate receptors. The results of this study show that the NAc-specific knock-down of RGS4 significantly increased the behaviors associated with morphine and did so by phosphorylation of the GluR1 (Ser831) and NR2A (Tyr1325) glutamate receptors in the NAc. Furthermore, the knock-down of RGS4 enhanced the phosphorylation of the GluR1 and NR2A glutamate receptors in the primary NAc/striatal neurons during spontaneous morphine withdrawal. These findings show a novel molecular mechanism of RGS4 in glutamatergic transmission that underlies the negative symptoms associated with morphine administration.

• The Korean Journal of Pain
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• v.26 no.1
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• pp.14-20
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• 2013

Background: Nefopam, a non-opiate analgesic, has been regarded as a substance that reduces the requirement for morphine, but conflicting results have also been reported. The inhibition of monoamine reuptake is a mechanism of action for the analgesia of nefopam. The spinal cord is an important site for the action of monoamines however, the antinociceptive effect of intrathecal nefopam was not clear. This study was performed to examine the antinociceptive effect of intrathecal (i.t.) nefopam and the pattern of pharmacologic interaction with i.t. morphine in the formalin test. Methods: Male Sprague-Dawley rats were implanted with an i.t. catheter, and were randomly treated with a vehicle, nefopam, or morphine. Formalin was injected into the hind-paw 10 min. after an i.t. injection of the above experiment drugs. After obtaining antinociceptive $ED_{50}$ of nefopam and morphine, the mixture of nefopam and morphine was tested for the antinociceptive effect in the formalin test at a dose of 1/8, 1/4, 1/2 of $ED_{50}$, or $ED_{50}$ of each drug followed by an isobolographic analysis. Results: Intrathecal nefopam significantly reduced the flinching responses in both phases of the formalin test in a dose-dependent manner. Its effect, however, peaked at a dose of $30{\mu}g$ in phase 1 (39.8% of control) and $10{\mu}g$ during phase 2 (37.6% of control). The isobolograhic analysis indicated an additive interaction of nefopam and morphine during phase 2, and a synergy effect in antinociception during phase 1. Conclusions: This study demonstrated that i.t. nefopam produces an antinociceptive effect in formalin induced pain behavior during both phases of the formalin test, while interacting differently with i.t. morphine, synergistically during phase 1, and additively during phase 2.

• The Korean Journal of Pain
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• v.34 no.2
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• pp.210-216
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• 2021

Background: Postherpetic neuralgia (PHN) is the most common complication of acute herpes zoster. The treatment of PHN remains a challenge for clinical pain management. Despite the effectiveness of anticonvulsants, antidepressants, and lidocaine patches in reducing PHN, many patients still face intractable pain disorders. In this randomized controlled study, we evaluated whether hydromorphone through intravenous patient-controlled analgesia (IV PCA) was effective in relieving PHN. Methods: Patients with PHN were randomly divided into two groups, one group received oral pregabalin with IV normal saline, another group received oral pregabalin with additional IV PCA hydromorphone for two weeks. Efficacy was evaluated at 1, 4, and 12 weeks after the end of the treatments. Results: Two hundred and one patients were followed up for 12 weeks. After treatment, numerical rating scale (NRS) score of patients in the hydromorphone group was significantly lower than that of the control group, and the difference of NRS scores between the two groups was statistically significant at 4 and 12 weeks after treatment. The frequency of breakthrough pain in the hydromorphone group was significantly lower than that in the control group 1 and 4 weeks after treatment. After treatment, the quality of sleep in the hydromorphone group was significantly improved compared with the control group. The most common adverse reactions in the hydromorphone group were dizziness and nausea, with no significant respiratory depression. Conclusions: IV PCA hydromorphone combined with oral pregabalin provides superior pain relief in patients with PHN, which is worthy of clinical application and promotion.