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Differential Actions of Intracerebroventricular Opioid Receptor Agonists on the Activity of Dorsal Horn Neurons in the Cat Spinal Cord (Opioid 수용체 효능제의 뇌실 내 주입이 고양이 척수후각세포의 활성에 미치는 영향)

  • 문태상;오우택
    • YAKHAK HOEJI
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    • v.43 no.4
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    • pp.411-418
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    • 1999
  • Intracerebroventricular (ICV) infusion of morphine (MOR) produces strong analgesia in man and animals. The analgesic effect is thought to be mediated by the centrifugal inhibitory control. But neural mechanisms of the analgesic effect of ICV morphine are not well understood. In the present study, we found that ICV MOR had dual actions on the activity of dorsal horn heurons: it produced both inhibition and excitation of dorsal horn neurons. Since MOR exerts its 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 intracerebroventricularly. Effects of ICV MOR were tested in 28 dorsal horn neurons of the spinal cord in the cat. ICV MOR inhibited, excited and did not affect the heat responses of dorsal horn neurons. ICV DAMGO and DADLE, $\mu$- and $\delta$-opioid agonist, respectively, exhibited the excitation of dorsal horn neurons. In contract, U-50488, a k-opioid agonist, exhibited both the inhibition and excitation of dorsal horn neurons. These results suggest that opioid receptors have different actions on activity of dorsal horn neuron and that the inhibitory action of k-opioid agonist may subserve the analgesia often produced by ICV MOR.

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Expression of TRP Channels in Mouse Dental Papilla Cell-23 (MDPC-23) Cell Line

  • Shin, Myoung-Sang;Yeon, Kyu-Young;Oh, Seog-Bae;Kim, Joong-Soo
    • International Journal of Oral Biology
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    • v.31 no.4
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    • pp.135-140
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    • 2006
  • Temperature signaling can be initiated by members of transient receptor potential (thermo-TRP) channels. Hot and cold substances applied to teeth usually elicit pain sensation. Since odontoblasts constitute a well-defined layer between the pulp and the mineralized dentin, being first to encounter thermal stimulation from oral cavity, they may be involved in sensory transduction process, in addition to their primary function as formation of dentin. We investigated whether thermo-TRP channels are expressed in a odontoblast cell line, MDPC-23. The expressions of thermo-TRP channels were examined using reverse transcription polymerase chain reaction (RT-PCR), immunohistochemistry, fluorometric calcium imaging. Analysis of RT-PCR revealed mRNA expression of TRPV1, TRPV2, TRPV4 and TRPM8, but no TRPV3, TRPA1. Immunohistochemical approach failed to detect TRPV1 expression. Whereas the application of 4-phorbol-12,13-didecanoate($10\;{\mu}M$, a TRPV4 agonist), menthol(1 mM, a TRPM8 agonist) and icilin($10\;{\mu}M$, a TRPM8 agonist) produced the enhancement of intracellular calcium concentration, capsaicin($1\;{\mu}M$, a TRPV1 agonist) did not. Our results suggest that subfamily of thermo-TRP channels expressed in odontoblasts may serve as thermal or mechanical transducer in teeth.

Synthesis of (${\pm}$)-cis-8-amino-l-2,3,4,4a,5,10b-hexahydrothiazolo[4,5-f]indeno [1,2-b][1,4]oxazine ((${\pm}$)-cis-8-Amino-2,3,4,4a,5,10b-hexahydrothiazolo[4,5-f]indeno [1,2-b][1,4]oxazine의 합성)

  • Ma, Eun-Sook
    • YAKHAK HOEJI
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    • v.52 no.6
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    • pp.488-493
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    • 2008
  • 2-Aminothiazole ring as a bioisoster of catechol in dopamine has provided with good oral availability and lipophilic property. 2-Aminoindan, is a rigid form of dopamine, was evaluated as a dopamine D3 agonist with low neurotoxicity. Dopamine D3 agonist was evaluated as selective for the treatment of Parkinson's disease. In order to develop a novel dopamine D3 agonist, we tried to synthesize the aminothiazoloindenoxazine derivative that is a hybrid structure of aminoindenoxazine and thiazole ring. cis-2-Amino-1-indanol (2) was synthesized from 1,2-indandione-2-oxime by catalytic hydrogenation and it was treated with chloroacetyl chloride and NaH in benzene solution to give (${\pm}$)-cis-4,4a,5,9b-tetrahydroindeno[1,2-b][1,4]oxazin-3(2H)-one (6). Nitration of 6 by the mixed acid gave 8-nitro compound (7) and the carbonyl group of 7 was reduced with $LiAlH_4$ to afford compound (8). 8 was reduced to form (${\pm}$)-cis-8-amino-2,3,4,4a,5,9b-hexahydroindeno[1,2-b][1,4]oxazine (9) and finally it was cyclized with KSCN in glacial acetic acid to yield (${\pm}$)-cis-8-amino-2,3,4,4a,5,10b-hexahydrothiazolo[4,5-f]indeno[1,2-b][1,4]oxazine (10).

Efficacy of Combined Aromatase Inhibitor and Luteinizing Hormone-Releasing Hormone Agonist in Premenopausal Metastatic Breast Cancer

  • Kim, Sang Hee;Choi, Jihye;Park, Chan Sub;Kim, Hyun-Ah;Noh, Woo Chul;Seong, Min-Ki
    • Journal of Breast Disease
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    • v.6 no.2
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    • pp.46-51
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    • 2018
  • Purpose: Endocrine therapy is the preferred treatment for hormone receptor (HR)-positive metastatic breast cancer (MBC). We investigated the efficacy of combined aromatase inhibitor (AI) and luteinizing hormone-releasing hormone (LHRH) agonist in premenopausal patients with HR-positive MBC. Methods: We retrospectively analyzed the medical records of 21 HR-positive premenopausal MBC patients treated with combined AI and LHRH agonist therapy. Results: The median follow-up period was 32.9 months. The overall response rate was 47.6%, with three complete responses (14.3%) and seven partial responses (33.3%). Nine patients (42.9%) achieved stable disease lasting more than 6 months; thus, the clinical benefit rate was 90.4%. The median time to progression was 45.4 months. No patients experienced grade 3 or 4 toxicity. Conclusion: Combined AI and LHRH agonist treatment safely and effectively induced remission or prolonged disease stabilization, suggesting that this could be a promising treatment option for HR-positive premenopausal patients with MBC.

Cyclooxygenase-2 Inhibitor Parecoxib Was Disclosed as a PPAR-γ Agonist by In Silico and In Vitro Assay

  • Xiao, Bin;Li, Dan-dan;Wang, Ying;Kim, Eun La;Zhao, Na;Jin, Shang-Wu;Bai, Dong-Hao;Sun, Li-Dong;Jung, Jee H.
    • Biomolecules & Therapeutics
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    • v.29 no.5
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    • pp.519-526
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    • 2021
  • In a search for effective PPAR-γ agonists, 110 clinical drugs were screened via molecular docking, and 9 drugs, including parecoxib, were selected for subsequent biological evaluation. Molecular docking of parecoxib to the ligand-binding domain of PPAR-γ showed high binding affinity and relevant binding conformation compared with the PPAR-γ ligand/antidiabetic drug rosiglitazone. Per the docking result, parecoxib showed the best PPAR-γ transactivation in Ac2F rat liver cells. Further docking simulation and a luciferase assay suggested parecoxib would be a selective (and partial) PPAR-γ agonist. PPAR-γ activation by parecoxib induced adipocyte differentiation in 3T3-L1 murine preadipocytes. Parecoxib promoted adipogenesis in a dose-dependent manner and enhanced the expression of adipogenesis transcription factors PPAR-γ, C/EBPα, and C/EBPβ. These data indicated that parecoxib might be utilized as a partial PPAR-γ agonist for drug repositioning study.

A Study of Clinical Efficacy of GnRH Antagonist (Cetrorelix) Single and Multiple Dose Protocol for Controlled Ovarian Hyperstimulation (과배란유도에서 GnRH Antagonist (Cetrorelix) Single 및 Multiple Dose Protocol의 임상적 효용성에 관한 연구)

  • Ko, Sang-Hyeon;Kim, Dong-Ho;Bae, Do-Hwan;Lee, Sang-Hoon
    • Clinical and Experimental Reproductive Medicine
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    • v.29 no.4
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    • pp.259-267
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    • 2002
  • Objective: This study was performed to compare the clinical outcomes of GnRH antagonist (Cetrorelix) single dose and multiple dose protocols for controlled ovarian hyperstimulation with GnRH agonist long protocol. Materials and Method: From September 2001 to March 2002, 48 patients (55 cycles) were performed controlled ovarian hyperstimulation for ART using by either GnRH antagonist and GnRH agonist. Single dose of 3 mg GnRH antagonist was administered in 15 patients (17 cycles, single dose group) at MCD #8 and multiple dose of 0.25 mg of GnRH antagonist was administered in 15 patients (18 cycles, multiple dose group) from MCD #7 to hCG injection day. GnRH agonist was administered in 18 patients (20 cycles, control group) by conventional GnRH agonist long protocol. We compared the implantation rate, number of embryos, and clinical pregnancy rate among three groups. Student-t test and Chi-square were used to determine statistical significance. Statistical significance was defined as p<0.05. Results: There were no significant differences in ampules of used gonadotropins, number of mature oocytes, obtained embryos between single and multiple dose group, but compared with control group, ampules of used gonadotropins, number of mature oocytes, obtained embryos were decreased significantly in both groups. Clinical pregnancy rate and implantation rate were not different in three groups. There were no premature LH surge and ovarian hyperstimulation syndrome in three groups. Multiple pregnancy were occurred 1 case in multiple dose group and 2 case in control group. Conclusions: GnRH antagonist is a safe, effective, and alternative method in the controlled ovarian hyperstimulation compared with GnRH agonist. Clinical outcomes and efficacy of both single and multiple dose protocol are similar between two groups.

Prediction and Prevention of Ovarian Hyperstimulation Syndrome (난소과자극증후군의 예측과 예방)

  • Kim, Hye-Ok;Kang, Inn-Soo
    • Clinical and Experimental Reproductive Medicine
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    • v.37 no.4
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    • pp.293-305
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    • 2010
  • Ovarian hyperstimulation syndrome (OHSS) is a life-threatening iatrogenic complication of ovulation induction. Before ovarian stimulation, identification of patients vulnerable to developing OHSS is necessary. And ovarian stimulation should be started with low doses of gonadotropin or GnRH antagonist protocol. During monitoring of ovarian stimulation with risk of OHSS, coasting, low doses hCG and GnRH agonist for triggering ovulation are considered. If severe OHSS is predicted, cycle cancellation and cryopreservation of all embryos should be considered to reduce late-onset OHSS and morbidity. And metformin and dopamine agonist for reducing OHSS are being proposed as a prophylactic treatment for OHSS.

Peroxisome proliferator-activated receptor ${\gamma}$ agonist suppresses human telomerase reverse transcriptase expression and aromatase activity in eutopic endometrial stromal cells from endometriosis

  • Chang, Hye Jin;Lee, Jae Hoon;Hwang, Kyung Joo;Kim, Mi Ran;Yoo, Jung Hyun
    • Clinical and Experimental Reproductive Medicine
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    • v.40 no.2
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    • pp.67-75
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    • 2013
  • Objective: To investigate the effect of peroxisome proliferator activated receptor ${\gamma}$(PPAR${\gamma}$) agonist on the cell proliferation properties and expression of human telomerase reverse transcriptase (hTERT) and aromatase in cultured endometrial stromal cell (ESC) from patients with endometriosis. Methods: Human endometrial tissues were obtained from women with endometriosis and healthy women (controls) using endometrial biopsy. Isolated ESCs were cultured and the cell proliferation was measured by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay and expression of hTERT, aromatase, and cyclooxygenase (COX)-2 by western blotting according to the addition of rosiglitazone (PPAR${\gamma}$ agonist). Results: We demonstrate that the cultured ESCs of endometriosis showed hTERT protein overexpression and increased cellular proliferation, which was inhibited by rosiglitazone, in a dose-dependent manner. At the same time, PPAR${\gamma}$ agonist also inhibited aromatase and COX-2 expression, resulting in decreased prostaglandin $E_2$ production in the ESCs of endometriosis. Conclusion: This study suggests that PPAR${\gamma}$ agonist plays an inhibitory role in the proliferative properties of eutopic endometrium with endometriosis by down-regulation of hTERT and COX-2 expression; this could be a new treatment target for endometriosis.

Therapeutic Effect of Epidurally Administered Lipo-Prostaglandin E1 Agonist in a Rat Spinal Stenosis Model

  • Park, Sang Hyun;Lee, Pyung Bok;Choe, Ghee Young;Moon, Jee Yeon;Nahm, Francis Sahngun;Kim, Yong Chul
    • The Korean Journal of Pain
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    • v.27 no.3
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    • pp.219-228
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    • 2014
  • Background: A lipo-prostaglandin E1 agonist is effective for the treatment of neurological symptoms of spinal stenosis when administered by an oral or intravenous route. we would like to reveal the therapeutic effect of an epidural injection of lipo-prostaglandin E1 on hyperalgesia in foraminal stenosis. Methods: A total of 40 male Sprague-Dawley rats were included. A small stainless steel rod was inserted into the L5/L6 intervertebral foramen to produce intervertebral foraminal stenosis and chronic compression of the dorsal root ganglia (DRG). The rats were divided into three groups: epidural PGE1 (EP) (n = 15), saline (n = 15), and control (n = 10). In the EP group, $0.15{\mu}g{\cdot}kg-1$ of a lipo-PGE1 agonist was injected daily via an epidural catheter for 10 days from postoperative day 3. In the saline group, saline was injected. Behavioral tests for mechanical hyperalgesia were performed for 3 weeks. Then, the target DRG was analyzed for the degree of chromatolysis, chronic inflammation, and fibrosis in light microscopic images. Results: From the fifth day after lipo-PGE1 agonist injection, the EP group showed significant recovery from mechanical hyperalgesia, which was maintained for 3 weeks (P < 0.05). Microscopic analysis showed much less chromatolysis in the EP group than in the saline or control groups. Conclusions: An epidurally administered lipo-PGE1 agonist relieved neuropathic pain, such as mechanical hyperalgesia, in a rat foraminal stenosis model, with decreasing chromatolysis in target DRG. We suggest that epidurally administered lipo-PGE1 may be a useful therapeutic candidate for patients with spinal stenosis.

Agonist-induced Desensitization of Muscarinic Acetylcholine Receptor in Rat Brain

  • Lee, Jong-Hwa;Esam-E.El-Fakahany
    • Archives of Pharmacal Research
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    • v.10 no.4
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    • pp.212-218
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    • 1987
  • Intact brain cell aggregates were dissociated from adult rat brains without cerebellum using a sieving technique. This proparation was used to elucidate the binding characteristics of agonist to muscarinic acetylcholine receptors (mAchR) in brain. Incubation of cells with carbamylcholine (carbachol) was shown agonist-induced receptor down-regulation depending on the concentration of agonist, not depending on the incubation time. This effect of carbachol was due to a reduction in the maximal binding capacity ($B_{max}$) to the mAchR without decreasing the affinity of the remaining receptors in incubation at 37.deg.C but was not apparent inincubation at $15^{\circ}}C$In addition, it was abolished when the receptors were blocked by atropine. The decline in ($^3H$)N-methylscopolamine (($^3H$)NMS) binding induced by agonist was reflected as a significant reduction in the receptor density with no change in receptor affinity, suggesting that 'true' receptor down-regulation takes place. Moreover, when the receptors were labeled with the lipophilic antagonist ($^3H$) quinuclidinyl benzilate (($^3H$) QNB) insted of the hydrophilic ligand ($^3H$)NMS, the magnitude of the observed receptor down-regulation was significantly lower in case of the former than the latter. This suggested that exposure of intact brain cells to muscarinic agonists might induce a slight degree of accumulation of receptors in intracellular sites before the receptors are actually degraded.

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