• Title/Summary/Keyword: Antagonists and Inhibitors

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Cytokines and Depression (사이토카인과 우울증)

  • Kim, Yong-Ku
    • Korean Journal of Biological Psychiatry
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    • v.15 no.3
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    • pp.175-185
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    • 2008
  • Accumulating evidence has suggested the existence of reciprocal communication between immune, endocrine, and neurotransmitter system. Cytokine hypothesis of depression implies that increased pro-inflammatory cytokine such as -1, IL-6, IL-12, TNF-${\alpha}$, and IFN-${\gamma}$ in major depression, acting neuromodulators, play a key role in the mediation of behavioral, neuroendocrine, and neurochemical disturbances in depression. Concerning the relation between cytokines and serotonin metabolism, pro-inflammatory cytokines have profound effects on the metabolism of brain serotonin through the enzyme indoleamine-2,3-dioxygenase(IDO) that metabolizes tryptophan, the precursor of 5-HT to neurodegenerative quinolinate and neuroprotective kynurenate. The neurodegeneration process is reinforced by the neurotoxic effect of the hypercortisolemia during depression. From this perspective, it is possible that efficacy of antidepressants in the treatment of depression may, at least in part, rely on downregulation of pro-inflammatory cytokine synthesis. So, the use of cytokine synthesis inhibitors or cytokine antagonists may be a new treatment approach in depression. However, at present the question whether cytokines play a causal role in the onset of depression or are mere epiphenomena sustaining depressive symptoms remains to be elucidated. Nevertheless, cytokine hypothesis has created new perspectives in the study of psychological and pathophysiological mechanism that are associated with major depression, as well as the prospect for developing a new generation antidepressants.

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Insect Juvenile Hormone Antagonists as Eco-friendly Insecticides (친환경 살충제로서의 곤충 유충호르몬 길항제)

  • Choi, Jae Young;Je, Yeon Ho
    • Korean journal of applied entomology
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    • v.61 no.1
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    • pp.101-108
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    • 2022
  • Because of their specificity to target insects and relatively low toxicity to non-target organisms, insect growth regulators (IGRs) have been regarded as attractive alternatives to chemical insecticides. Commercially available IGRs are classified into juvenile hormone agonists (JHAs), ecdysone agonists (EAs), and chitin synthesis inhibitors (CSIs) according to their mode of action. Recently, JH-mediated interaction of methoprene-tolerant (Met), which is JH receptor, and its binding partners have been replicated in vitro using yeast cells transformed with the Met and FISC/CYC genes of A. aegypti. Using this in vitro yeast two-hybrid β-galactosidase assay, juvenile hormone antagonists (JHANs) have been identified from various sources including chemical libraries, plants, and microorganisms. As juvenile hormone (JH) is an insect specific hormone and regulates development, reproduction, diapause and other physiological processes, JHANs fatally disrupt the endocrine signals, which result in abnormal development and larval death. These results suggested that JHANs could be efficiently applied as IGR insecticides with a broad insecticidal spectrum. This review discuses JH signaling pathway mediated by Met and future prospects of JHANs as environmentally benign IGR insecticides.

Anti-inflammatory and antinociceptive effects of sitagliptin in animal models and possible mechanisms involved in the antinociceptive activity

  • Valiollah Hajhashemi;Hossein Sadeghi;Fatemeh Karimi Madab
    • The Korean Journal of Pain
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    • v.37 no.1
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    • pp.26-33
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    • 2024
  • Background: Sitagliptin is an antidiabetic drug that inhibits dipeptidyl peptidase-4 enzyme. This study aimed to investigate the antinociceptive and anti-inflammatory effects of sitagliptin in formalin and carrageenan tests and determine the possible mechanism(s) of its antinociceptive activity. Methods: Male Swiss mice (25-30 g) and male Wistar rats (180-220 g) were used for formalin and carrageenan tests, respectively. In the formalin test, paw licking time and in the carrageenan test, paw thickness were considered as indexes of pain behavior and inflammation respectively. Three doses of sitagliptin (2.5, 5, and 10 mg/kg) were used in these tests. Also, several antagonists and enzyme inhibitors were used to evaluate the role of adrenergic, serotonergic, dopaminergic, and opioid receptors as well as the NO/cGMP/KATP pathway in the antinociceptive effect of sitagliptin (5 mg/kg). Results: Sitagliptin showed significant antinociceptive and anti-inflammatory effects in the formalin and carrageenan tests respectively. In the carrageenan test, all three doses of sitagliptin significantly (P < 0.001) reduced paw thickness. Pretreatment with yohimbine, prazosin, propranolol, naloxone, and cyproheptadine could not reverse the antinociceptive effect of sitagliptin (5 mg/Kg), which indicates that adrenergic, opioid, and serotonin receptors (5HT2) are not involved in the antinociceptive effects. L-NAME, methylene blue, glibenclamide, ondansetron, and sulpiride were able to reverse this effect. Conclusions: NO/cGMP/KATP, 5HT3 and D2 pathways play an important role in the antinociceptive effect of sitagliptin. Additionally significant anti-inflammatory effects observed in the carrageenan test might contribute in reduction of pain response in the second phase of the formalin test.

Pharmacologic Management of Chronic Pain

  • Park, Hue-Jung;Moon, Dong-Eon
    • The Korean Journal of Pain
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    • v.23 no.2
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    • pp.99-108
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    • 2010
  • Chronic pain is a multifactorial condition with both physical and psychological symptoms, and it affects around 20% of the population in the developed world. In spite of outstanding advances in pain management over the past decades, chronic pain remains a significant problem. This article provides a mechanism- and evidence-based approach to improve the outcome for pharmacologic management of chronic pain. The usual approach to treat mild to moderate pain is to start with a nonopioid analgesic. If this is inadequate, and if there is an element of sleep deprivation, then it is reasonable to add an antidepressant with analgesic qualities. If there is a component of neuropathic pain or fibromyalgia, then a trial with one of the gabapentinoids is appropriate. If these steps are inadequate, then an opioid analgesic may be added. For moderate to severe pain, one would initiate an earlier trial of a long term opioid. Skeletal muscle relaxants and topicals may also be appropriate as single agents or in combination. Meanwhile, the steps of pharmacologic treatments for neuropathic pain include (1) certain antidepressants (tricyclic antidepressants, serotonin and norepinephrine reuptake inhibitors), calcium channel ${\alpha}2-{\delta}$ ligands (gabapentin and pregabalin) and topical lidocaine, (2) opioid analgesics and tramadol (for first-line use in selected clinical circumstances) and (3) certain other antidepressant and antiepileptic medications (topical capsaicin, mexiletine, and N-methyl-d-aspartate receptor antagonists). It is essential to have a thorough understanding about the different pain mechanisms of chronic pain and evidence-based multi-mechanistic treatment. It is also essential to increase the individualization of treatment.

A Study about the Mechanism of $Ca^{2+}$ and Pi Homeostasis by Estradiol 17$\beta$ in Proximal Tubule Cells in the Osteoporosis

  • Han Ho-jae;Park Soo-Hyun
    • Biomedical Science Letters
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    • v.10 no.4
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    • pp.375-383
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    • 2004
  • It has been reported that osteoporosis induced by the deficiency of estrogens in menopause is associated with the unbalance of Ca/sup 2+/ and Pi levels. Proximal tubule is very important organ to regualte Ca/sup 2+/ and Pi level in the body. However, the effect of estrogens on Ca/sup 2+/ and Pi regulation was not elucidated. Thus, we examined the effect of 17-β estradiol (E₂) on Ca/sup 2+/ and Pi uptake in the primary cultured rabbit renal proxiaml tubule cells. In the present study, E₂(> 10/sup -9/M) decreases Ca/sup 2+/uptake and stimulates Pi uptake over 3 days. E₂-induced decrease of Ca/sup 2+/ uptake and stimulation of Pi uptake were blocked by actinomycin D (a gene transcription inhibitor), cycloheximide (a protein synthesis inhibitor). tamoxifen, and progesterone (estrogen receptor antagonists). E₂-induced decrease of Ca/sup 2+/ uptake and stimulation of Pi uptake were blocked by SQ22536 (an adenylate cyclase inhibitor), Rp-cAMP (a cAMP antagonist), and PKI (a protein kinase A inhibitor). Indeed, E₂ increased cAMP formation. In addition, E₂-induced decrease of Ca/sup 2+/ uptake and stimulation of Pi uptake were blocked by staurosporine, H-7, and bisindolylmaleimide I (protein kinase C inhibitors) and E₂ translocated PKC from cytoslic fraction to membrane fraction. In conclusion, E₂ decreased Ca/sup 2+/ uptake and stimulated Pi uptake via cAMP and PKC pathway in the PTCs.

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Anti-allodynic Efficacy of NMDA Antagonist Peptide and Noradrenaline Alone and in Combination in Rodent Neuropathic Pain Model

  • Nasirinezhad, Farinaz;Hosseini, Marjan;Salari, Sajad
    • The Korean Journal of Pain
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    • v.28 no.2
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    • pp.96-104
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    • 2015
  • Background: The present experiment was conducted to identify the cooperative effect of serine histogranin (SHG) and noradrenaline in alleviating peripheral neuropathic pain. Methods: Chronic constriction injury of the right sciatic nerve was used to induce chronic neuropathic pain. For drug delivery, a PE10 tube was inserted into the subarachnoid space. Acetone drops and a $44^{\circ}C$ water bath were used to evaluate the cold and heat allodynia, respectively. Placing and grasping reflexes were used to assess the locomotor system. Results: SHG at 0.5 and $1{\mu}g$significantly (P < 0.05) decreased the thermal allodynia. The cold allodynia was also significantly reduced by intrathecal injections of 0.5 (P < 0.05) and $1{\mu}g$(P < 0.001) of SHG. $1{\mu}g$of noradrenaline, but not $0.5{\mu}g$, significantly alleviated the cold (P < 0.01) and thermal (P < 0.05) allodynia. The ameliorating effect of noradrenaline or SHG disappeared when the two compounds were administrated in equal concentrations. A significant difference (P < 0.01 in the acetone and P < 0.05 in the heat) was observed in the groups under equal doses of the two compounds, with a lower effectiveness of the combination therapy. Conclusions: Our findings suggest that the simultaneous administrations of noradrenaline and SHG do not result in synergistic analgesia, and combination therapy may not be a good approach to the treatment of chronic neuropathic pain syndrome.

Impact of hormonal therapy and other adjuvant therapies on contralateral breast volume change after implant-based breast reconstruction

  • Park, Jung Youl;Chung, Jae-Ho;Lee, Hyung Chul;Lee, Byung-Il;Park, Seung-Ha;Yoon, Eul-Sik
    • Archives of Plastic Surgery
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    • v.45 no.5
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    • pp.432-440
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    • 2018
  • Background Adjuvant therapy after breast surgery, including tamoxifen or aromatase inhibitors, improves the postoperative outcomes and long-term survival of breast cancer patients. The aim of this study was to determine whether volume changes occurred in the contralateral breast during hormonal or other adjuvant therapies. Methods This study reviewed 90 patients who underwent unilateral breast reconstruction between September 2012 and April 2018 using tissue expanders and a permanent implant after the surgical removal of breast cancer. The volume of the contralateral breast was measured using a cast before the first (tissue expander insertion) and second (permanent implant change) stages of surgery. Changes in breast volume were evaluated to determine whether adjuvant therapy such as hormonal therapy, chemotherapy, and radiation therapy influenced the volume of the contralateral breast. Results The group receiving tamoxifen therapy demonstrated a significant decrease in volume compared with the group without tamoxifen (-7.8% vs. 1.0%; P=0.028). The aromatase inhibitor-treated group showed a significant increase in volume compared with those who did not receive therapy (-6.2% vs. 4.5%; P=0.023). There were no significant differences between groups treated with other hormonal therapy, chemotherapy, or radiation therapy. Conclusions Patients who received tamoxifen therapy showed a significant decrease in volume in the contralateral breast, while no significant change in weight or body mass index was found. Our findings suggest that we should choose smaller implants for premenopausal patients, who have a high likelihood of receiving tamoxifen therapy.

Synthesis and SAR of N-Chlorophenyl Substituted Piperrazinylethyl-aminomethylpyrazoles as 5-HT3A Inhibitors

  • Lee, Byung-Hwan;Choi, In-Sung;Rhim, Hye-Whon;Choi, Kyung-Il;Nah, Seung-Yeol;Nam, Ghil-Soo
    • Bulletin of the Korean Chemical Society
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    • v.30 no.11
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    • pp.2707-2712
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    • 2009
  • 5-$HT_{3}$ receptor;5-$HT_{3A}$ receptor channel activity;Novel 5-$HT_{3}$ receptor channel current blockers;Chlorophenyl substituted piperazinylethylaminomethylpyrazoles; The 5-$HT_{3A}$ receptors are one of ligand-gated ion channels and are known to be involved in visceral pain, anxiety, or anticancer agent-induced nausea and vomiting. In present study, we designed novel skeletons based on the developed 5-$HT_{3}$ receptor antagonists and evaluated their effects on 5-$HT_{3A}$ receptor channel currents ($I_{5-HT}$) of a series of pyrazole derivatives having N-chlorophenylpiperazine functionality (6-9). We found that most of N-p-chlorophenyl substituted piperazinyl-pyrazole derivatives (7b, 7c, 7e and 7h) exhibited the high potency for the inhibition of $I_{5-HT}$, whereas the compound without chloride (6) or with m-chlorophenyl group (a serious of 8 and 9) showed the low potency. These result indicate that p-chlorophenyl group is might play an important role for increasing the inhibitory potency on $I_{5-HT}$.

The Altered Signaling on EFS-Induced Colon Contractility in Diabetic Rats

  • Thein, Wynn;Po, Wah Wah;Kim, Dong Min;Sohn, Uy Dong
    • Biomolecules & Therapeutics
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    • v.28 no.4
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    • pp.328-336
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    • 2020
  • Diabetes mellitus affects the colonic motility developing gastrointestinal symptoms, such as constipation. The aim of the study was to examine the role of intracellular signaling pathways contributing to colonic dysmotility in diabetes mellitus. To generate diabetes mellitus, the rats were injected by a single high dose of streptozotocin (65 mg/kg) intraperitoneally. The proximal colons from both normal and diabetic rats were contracted by applying an electrical field stimulation with pulse voltage of 40 V in amplitude and pulse duration of 1 ms at frequencies of 1, 2, 4, and 6 Hz. The muscle strips from both normal rats and rats with diabetes mellitus were pretreated with different antagonists and inhibitors. Rats with diabetes mellitus had lower motility than the control group. There were significant differences in the percentage of inhibition of contraction between normal rats and rats with diabetes mellitus after the incubation of tetrodotoxin (neuronal blocker), atropine (muscarinic receptor antagonist), prazosin (α1 adrenergic receptor antagonist), DPCPX (adenosine A1 receptor antagonist), verapamil (L-type Ca2+ channel blocker), U73122 (PLC inhibitor), ML-9 (MLCK inhibitor), udenafil (PDE5 inhibitor), and methylene blue (guanylate cyclase inhibitor). The protein expression of p-MLC and PDE5 were decreased in the diabetic group compared to the normal group. These results showed that the reduced colonic contractility resulted from the impaired neuronal conduction and decreased muscarinic receptor sensitivity, which resulted in decreased phosphorylation of MLC via MLCK, and cGMP activity through PDE5.

Pharmacodynamic Drug-Drug Interactions Considered to be Added in the List of Contraindications with Pharmacological Classification in Korea (약물군-약물군 조합으로 도출한 약력학적 기전의 추가 병용금기성분)

  • Je, Nam Kyung;Kim, Dong-Sook;Kim, Grace Juyun;Lee, Sukhyang
    • Korean Journal of Clinical Pharmacy
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    • v.25 no.2
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    • pp.120-129
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    • 2015
  • Objectives: Drug utilization review program in Korea has provided 'drug combinations to avoid (DCA)' alerts to physicians and pharmacists to prevent potential adverse drug events or inappropriate drug use. Seven hundred and six DCA pairs have been announced officially by the Ministry of Food and Drug Safety (MFDS) by March, 2015. Some DCA pairs could be grouped based on the drug interaction mechanism and its consequences. This study aimed to investigate the drug-drug interaction (DDI) pairs, which may be potential DCAs, generated by the drug class-drug class interaction method. Methods: Eleven additive/synergistic and one antagonistic drug class-drug class interaction groups were identified. By combining drugs of two interacting drug class groups, numerous DDI pairs were made. The status and severity of DDI pairs were examined using Lexicomp and Micromedex. Also, the DCA listing rate was calculated. Results: Among 258 DDI pairs generated by the drug class-drug class interaction method, only 142 pairs were identified as official DCA pairs by the MFDS. One hundred and four pairs were identified as potential DCA pairs to be listed. QT prolonging agents-QT prolonging agents, triptans-ergot alkaloids, tricyclic antidepressants-monoamine oxidase inhibitors, and dopamine agonists-dopamine antagonists were identified as drug class-drug class interaction groups which have less than 50 % DCA listing rate. Conclusion: To improve the clinicians' adaptability to DCA alerts, the list of DCA pairs needs to be continuously updated.