• Title/Summary/Keyword: Neurotransmitter receptor

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The Analgesic Effect and its Merchanism of Bee Venom Acupuncture in the Collagen-induced Arthritis Rats (봉독약침이 collagen 유발 관절염에 미치는 진통효과 및 그 기전 연구)

  • Jung, In-tae;Baek, Yong-hyeon;Park, Dong-suk;Choi, Do-young
    • Journal of Acupuncture Research
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    • v.22 no.1
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    • pp.99-108
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    • 2005
  • Objective : The aim of this study is to investigate the analgesic effect and its mechanism of bee venom acupuncture on collagen-induced arthritis(CIA) rats. Methods : Bee venom (1 mg/kg) was subcutaneously punctured into Choksamni (ST36) of CIA Analgesic effect was evaluated by using the tail flick latency (TFL). Opioid and ${\alpha}2$-adrenergic neurotransmitter system were examined by naloxone as an opioid receptor antagonist and yohimbine as ${\alpha}2$-adrenoceptor antagonist prior to bee venom cupuncture. Results : The results were as follows; 1. The TFL for the CIA rat was decreased as time went by. 2. The TFL in CIA rat was increased in bee venom acupuncture group compared with control group (no treatment). 3. Analgesic effect of bee venom acupuncture was not abolished by naloxone pre-treatment in the CIA rat. 4. Analgesic effect of bee venom aqua-acupuncture was abolished by yohimbine pre-treatment in the CIA rat. 5. Two weeks bee venom acupuncture had the continous analgesic effect for 4 weeks. Conclusions : Bee venom acupuncture has an analgesic effect on the CIA rat and has an antinociception mediated by ${\alpha}2$-adrenergic system.

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Inhibitory Effects of ${\gamma}$-Aminobutyric Acid on the Contractility of Isolated Rat Vas Deferens (흰쥐의 적출 정관 수축성에 대한 ${\gamma}$-Aminobutyric Acid의 억제작용)

  • Ahn, Ki-Young;Kwon, Oh-Cheol;Ha, Jeoung-Hee;Lee, Kwang-Youn;Kim, Won-Joon
    • Journal of Yeungnam Medical Science
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    • v.9 no.2
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    • pp.382-395
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    • 1992
  • GABA is an inhibitory neurotransmitter in central nervous system and produce sedative, antianxiety and muscle reaxing effects via $GABA_A$ receptor or $GABA_B$ receptor. Recently it is known that GABA is widely distributed throughout peripheral organs and may playa physiological role in certain organ. The vas deferens is innervated by species-difference. These study, therefore, was performed to investigate the mode and the mechanism of action of GABA on the norepiniphrine-, ATP- and electric stimulation-induced contraction of vas deferens of rat. Sprague-Dawley rats were sacrificed by cervical dislocation. The smooth muscle strips were isolated from the prostastic portion and were mounted in the isolated muscle bath. PSS in the bath was aerated with 95/5%-$O_2/CO_2$ at $33^{\circ}C$. Muscle tensions were measured by isometric tension transducer and were recorded by biological recording system. 1. GABA, muscimol, a $GAB_A$ agonist, and baclofen, a $GABA_B$ agonist inhibited the electric field stimulation(EFS, 0.2Hz, 1mSec, 80 V, monophasic square wave)-induced contraction with a rank order of potency of GABA greater than baclofen greater than muscimol. 2. The inhibitory effect of GABA was antagonized by delta aminovaleric acid(DAVA), a $GABA_B$ antagonist, but not by bicuculline, a $GABA_A$ mtagonist. 3. The inhibitory effect of baclofen was antagonized by DAVA, but the effect of muscimol was not antagonized by bicuculline. 4. Exogenous norepinephrine(NE) and ATP contracted muscle strip concentration dependently, but the effect of acetylcholine was negligible : and GABA did not affect the NE-and ATP-induced contractions. 5. GABA, baclofen and muscimol did not affect basal tone, and GABA did not affect the NE-and ATP-induced contractionsm 6. EFS-induced contraction was including 2 distinctable components. The first phasic component was inhibited by beta gamma-methylene ATP(mATP), a desensitizing agent of APT receptor and the second tonic component was reduced by pretreatment of reserpine(3 mg/Kg, IP). 7. GABA inhibited the EFS-induced contraction of reserpinized strips, but not the mATP-treated strips. These results suggest that in the prostatic portion of the rat vas deferens, adrenergic and purinergic neurotransmissions are exist, and GABA inhibits the release of ATP via presynaptic $GABA_B$ receptor on the excitatory neurons.

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Interrelationship between Dopaminergic Receptors and Catecholamine Secretion from the Rat Adrenal Gland (흰쥐 부신에서 카테콜아민 분비작용과 도파민 수용체간의 상관성)

  • Lim, Dong-Yoon;Yoon, Joong-Keun;Moon, Baek
    • The Korean Journal of Pharmacology
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    • v.30 no.1
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    • pp.87-100
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    • 1994
  • It has been known for some time that dopamine-containing cells are existed in sympathetic ganglia, i.e., small, intensely fluorescent cells. However, its role and mechanism of action as a peripheral neurotransmitter are poorly understood so far. In the present study, an attempt was made to examine the effect of apomorphine, which is known to be a selective agonist of dopaminergic $D_2$. receptor on secretion of catecholamines (CA) from the isolated perfused rat adrenal gland. The perfusion of a low concentration of 10uM apomorphine into an adrenal vein for 20 min produced significant reduction in CA secretion induced by 5.32 mM ACh, 56 mM KCl, 100 uM DMPP and 100 uM McN-A-343. Increasing apomorphine concentration to 30 uM led to more markedly decreased CA secretion as compared to the case of 10 uM apomorphine and also did inhibit clearly CA release by $10^{-5}M$ Bay-K-8644. Furthermore, in adrenal glands preloaded with a higher dose of 100 uM apomorphine, CA releases evoked by ACh, excess $K^+$, DMPP and McN-A-343 were almost abolished by the drug. The perfusion of $3.3{\pm}10^{-5}M$ metoclopramide, which is well-known as a selective dopaminergic $D_2$ antagonist, produced significantly inhibitory effect of CA release by ACh, DMPP and McN-A-343 but did not affect that by excess $K^+$. However, preloading of 30uM apomorphine in the presence of metoclopramide did not modify the CA secretory effect of excess $K+$ and DMPP. These experimental results demonstrate that apomorphine causes dose-dependent inhibition of CA secretion by cholinergic receptor stimulation and also by membrane depolarization from the isolated perfused rat adrenal gland, suggesting that these effects appear to be exerted by inhibiting influx of extracellular calcium into the rat adrenal medullary chromaffin cells through activation of inhibitory dopaminergic receptors.

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Ethanolic Extract of the Seed of Zizyphus jujuba var. spinosa Ameliorates Cognitive Impairment Induced by Cholinergic Blockade in Mice

  • Lee, Hyung Eun;Lee, So Young;Kim, Ju Sun;Park, Se Jin;Kim, Jong Min;Lee, Young Woo;Jung, Jun Man;Kim, Dong Hyun;Shin, Bum Young;Jang, Dae Sik;Kang, Sam Sik;Ryu, Jong Hoon
    • Biomolecules & Therapeutics
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    • v.21 no.4
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    • pp.299-306
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    • 2013
  • In the present study, we investigated the effect of ethanolic extract of the seed of Zizyphus jujuba var. spinosa (EEZS) on cholinergic blockade-induced memory impairment in mice. Male ICR mice were treated with EEZS. The behavioral tests were conducted using the passive avoidance, the Y-maze, and the Morris water maze tasks. EEZS (100 or 200 mg/kg, p.o.) significantly ameliorated the scopolamine-induced cognitive impairment in our present behavioral tasks without changes of locomotor activity. The ameliorating effect of EEZS on scopolamine-induced memory impairment was significantly reversed by a sub-effective dose of MK-801 (0.0125 mg/kg, s.c.). In addition, single administration of EEZS in normal naive mouse enhanced latency time in the passive avoidance task. Western blot analysis was employed to confirm the mechanism of memory-ameliorating effect of EEZS. Administration of EEZS (200 mg/kg) increased the level of memory-related signaling molecules, including phosphorylation of extracellular signal-regulated kinase or cAMP response element-binding protein in the hippocampal region. Also, the time-dependent expression level of brain-derived neurotrophic factor by the administration of EEZS was markedly increased from 3 to 9 h. These results suggest that EEZS has memory-ameliorating effect on scopolamine-induced cognitive impairment, which is mediated by the enhancement of the cholinergic neurotransmitter system, in part, via NMDA receptor signaling, and that EEZS would be useful agent against cognitive dysfunction such as Alzheimer's disease.

Effects of Locus Coeruleus/Subcoeruleus Stimulation on the Tail Flick Reflex and Efflux of Noradrenaline into the Spinal Cord Superfusates (청반핵 자극으로 인한 노르아드레날린의 유리가 동통의 조절에 미치는 영향)

  • Park, Kyung-Pyo;Kim, Jong-Sung;Suh, Dae-Chul;Park, Hyoung-Sup
    • The Korean Journal of Pharmacology
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    • v.30 no.1
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    • pp.29-37
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    • 1994
  • Inhibition of the nociceptive Tail Flick Reflex (TFR) was observed with electrical stimulation of the locus coeruleus/subcoeruleus (LC/SC) in the male Sprague - Dawley rats under light anesthesia, and the involved neurotransmitter (s) were characterized. Electrical stimulation of LC/SC induced the analgesia with the stimulation threshold (intensity of the current, given for 100 usec and in 100 Hz frequency, which caused the TF latency longer than 6.5 sec) around 55 uA. Intrathecal administrations of ${\alpha}_2$ antagonist, yohimbine (30 ug) or opioid antagonist, naloxone (20 ug) increased the stimulation threshold by 147% and 123% respectively (from 55 uA to 135 uA,9 and from 54 uA to 123 uA;P0.01, n=5, each). The basal TF latency without stimulation (3.1 sec) was reduced by the antagonists (to 2.5 sec by yohimbine, p<0.05, n=5; to 2.6 sec by naloxone, p<0.1, n=5), vehicle only did not show any effect. Noradrenaline(NA) in the spinal cord superfusates measured with HPLC was increased by the LC/SC stimulation, from 4.18 ng/ml before to 7.74 ng/ml after stimulation (P<0.05, n=10). The result suggest that analgesia induced by LC/SC stimulation is mediated, at least in part, by the noradrenergic system in which ${\alpha}_2$ receptor is involved, as well as the opioid system.

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