• Title/Summary/Keyword: $AT_1$ receptor antagonist

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Novel Glycolipoproteins from Ginseng

  • Pyo, Mi-Kyung;Choi, Sun-Hye;Hwang, Sung-Hee;Shin, Tae-Joon;Lee, Byung-Hwan;Lee, Sang-Mok;Lim, Yoong-Ho;Kim, Dong-Hyun;Nah, Seung-Yeol
    • Journal of Ginseng Research
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    • v.35 no.1
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    • pp.92-103
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    • 2011
  • Ginseng has been used as a general tonic agent to invigorate human body. In the present study, we isolated novel glycolipoproteins from ginseng that activate $Ca^{2+}$-activated $Cl^-$ channel (CaCC) in Xenopus oocytes and transiently increase intracellular free $Ca^{2+}$ concentration ($[Ca^{2+}]_i$) in mouse Ehrlich ascites tumor cells. We named the active ingredients as gintonin. Gintonin exists in at least six different forms. The native molecular weight of gintonin is about 67 kDa but its apparent molecular weight is about 13 kDa, indicating that gintonin might be a pentamer. Gintonin is rich in hydrophobic amino acids. Its main carbohydrates are glucose and glucosamine. Its lipid components are linoleic, palmitic, oleic, and stearic acids. Gintonin actions were blocked by U73122, a phospholipase C inhibitor, 2-aminoethxydiphenyl borate, an inositol 1,4,5-trisphosphate receptor antagonist, or bis (o-aminophenoxy) ethane-N,N,N0,N0-tetracetic acid acetoxymethyl ester, a membrane permeable $Ca^{2+}$ chelator. In the present study, we for the first time isolated novel gintonin and showed the signaling pathways on gintonin-mediated CaCC activations and transient increase of $[Ca^{2+}]_i$. Since $[Ca^{2+}]_i$ as a second messenger plays a pivotal role in the regulation of diverse $Ca^{2+}$-dependent intracellular signal pathways, gintonin-mediated regulations of $[Ca^{2+}]_i$ might contribute to biological actions of ginseng.

Prolactin Response to Cimetidine in the Schizophrenics - In Unmedicated Male Positive and Negative Patients - (정신분열증 환자에서 Cimetidine에 의한 Prolactin 분비 반응 - 양성 및 음성 아형 남자 환자에서 -)

  • Jin, Hyuk Hee;Kwon, Young Joon;Jeong, Hee Yeon;Han, Sun Ho
    • Korean Journal of Biological Psychiatry
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    • v.3 no.1
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    • pp.121-126
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    • 1996
  • Objects : There is considerable interest in the role of serotonin(5-HT) in the pathophysiology of schizophrenia. Cimetidine, $H_2$ antagonist, produces transient increase in serum prolactin(PRL) levels by indirect serotonergic mechanism in man following intravenous administration. Therefore the authors investigated the effects of cimetidine on serum PRL levels of male unmedicated schizophrenics. Method : Baseline serum prolactin level and psychopathology were measured at 9:00 AM. in the two groups(12 positive schizophrenics, 7 negative schizophrenics) and $T_{30}$ levels were measured 30 minutes after intravenous injection of cimetidine (ie, 9:30 AM) Results: 1) Baseline prolactin levels were not different in the three groups. 2) Prolactin levels of 30 minutes after intravenous injection of cimetidine($T_{30}$) compared with baseline prolactin levels were increased all in the three groups. 3) Degrees of interval change from baseline to $T_{30}$ were significantly different between normal control and negative schizophrenics(p<0.05). Conclusion : The prolactin response to cimetidine was significantly blunted in negative male schizophrenics than normal control. These data are consistent with the hypothesis of an abnormality of serotonergic activity, including down-regulation $5-HT_2$ receptors, in male negative schizophrenics.

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Effect of Ketamine on the Oxidative Burst Activity of Canine Peripheral Blood Leukocytes In Vitro (In Vitro에서 개 말초혈액 백혈구의 순간산소과소비현상에 대한 케타민의 효과)

  • Kim, Min-Jun;Kang, Ji-Houn;Yang, Mhan-Pyo
    • Journal of Veterinary Clinics
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    • v.23 no.4
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    • pp.393-399
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    • 2006
  • Ketamine, one of general anesthetics for human and veterinary use, is a non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist which interferes with the action of excitatory amino acids. It has been reported to impair various leukocyte functions. In this study, the effect of ketamine on the oxidative burst activity (OBA) of canine peripheral blood leukocytes was examined. The OBA of canine peripheral blood phagocytes was analyzed by flow cytometry system. Ketamine at higher concentration such as $1,000{\mu}M$ exhibited a low viability of leukocytes. Thus, ketamine was used at concentration of 10 to $500{\mu}M$ showing no cytotoxic effect and high cell viability. The OBA of leukocytes in the presence or absence of latex beads was analyzed by addition of dihydrorhodamine 123. The direct treatment of ketamine revealed the inhibitory effect on the OBA of peripheral blood polymorphonuclear cells (PMN) and monocyte-rich cells but not peripheral blood mononuclear cells (PBMC) in the presence of latex beads. However, when latex beads were not added to PMN, its OBA was not inhibited by ketamine. The OBA of PMN and monocyte-rich cells but not PBMC in the presence of latex beads was also inhibited by culture supernatant from ketamine-treated- PBMC but not -PMN. But the OBA of PMN in the absence of latex beads was not inhibited by culture supernatant from PBMC treated with ketamine. Therefore, these results suggested that ketamine has the inhibitory effect on the OBA of canine peripheral blood phagocytes such as neutrophils and monocytes during phagocytic response.

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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Shipyeukmiyeugi-eum Extracts Suppressed Tumor Growth through Immunomodulatory Effects on MCF-7 (십육미유기음(十六味流氣飮)의 면역활성(免疫活性)에 의한 유방암(乳房癌) 세포 성장억제효과(成長抑制效果))

  • Jung, Yeon-Chul;Park, Young-Sun;Kim, Dong-Chul
    • The Journal of Korean Obstetrics and Gynecology
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    • v.25 no.3
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    • pp.40-60
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    • 2012
  • Objectives: The object of this study was to observe antitumor, anticachexia and immunomodulatory effects of Shipyeukmiyeugi-eum(SYM) on human breast cancer cell, MCF-7, xenograft Balb/c nu-nu nude mice. Methods: Three different dosages of SYM-125, 250 and 500 mg/kg were orally administered once a day for 28 days from 11 days after tumor cell inoculation, and the changes on the body weights, tumor volume and weights, weights of spleen and popliteal lymph node and epididymal fat, serum IL-6 and IFN-${\gamma}$ levels, NK cell and peritoneal macrophage activities, splenic TNF-${\alpha}$, IL-$1{\beta}$ and IL-10 contents were observed. In addition, histopathological observations of apoptotic cell, spleen, popliteal lymph node and cervical brown adipose were also detected. The results were compared with a potent cytotoxic estrogen receptor antagonist, Tamoxifen 20 mg/kg treated mice. Results: Tumor volumes and weights were decreased without cytotoxic effects on the both MCF-7 and MCF-10A cells as results of all three different dosages of SYM treatment. And weights of body, spleen, popliteal lymph node, epididymal fat, serum IFN-${\gamma}$, NK cell, peritoneal macrophage activities, splenic TNF-${\alpha}$, IL-$1{\beta}$ and IL-10 contents were increased with decrease of serum IL-6. At histopathological observations, apoptotic tumor cells, spleen, popliteal lymph node and cervical brown adipose tissue were increased. That means tumor-related immunosuppress and cachexia were markedly inhibited by SYM treatment as compared with tumor-bearing mice. On the other hand, Tamoxifen showed marked cytotoxic effects against MCF-7 and MCF-10A, decreases of tumor volume and weights, and increases of apoptotic tumor cells and related decreases of tumor cell volumes, but tamoxifen markedly deteriorated the tumor-related immune-suppress and cachexia. Conclusions: The results obtained in this study suggest that SYM showed favorable anticancer effects and anticachexic effects on the MCF-7 cell xenograft through immunomodulatory effects. SYM did not induce any cytotoxic effects against both normal and cancer cells.

Cytoprotective Effect of Zinc-Mediated Antioxidant Gene Expression on Cortisol-Induced Cytotoxicity (Cortisol 유발 세포독성에 대한 아연 관련 항산화 유전자 발현 증가에 의한 세포보호 효과)

  • Chung, Mi Ja;Kim, Sung Hyun;Hwang, In Min
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.44 no.5
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    • pp.649-656
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    • 2015
  • The protective effect of zinc against cortisol-induced cell injury was examined in rainbow trout gill epithelial cells. Cells exposed to cortisol for 24 h showed increased leakage of lactate dehydrogenase (LDH) as well as decreased cell viability in a dose-dependent manner. Treatment with zinc ($100{\mu}M$ $ZnSO_4$) reduced the severity of both LDH release and cell death as well as protected cells against cortisol-induced caspase-3 activation, indicating reduction of apoptosis. Cortisol-induced cell death, leakage of LDH, and caspase-3 activation were blocked by the glucocorticoid receptor antagonist Mifepristone (RU-486), suggesting that cell injury was cortisol-dependent. In addition, we studied the effect of zinc on the expression of antioxidant genes such as metallothionein A (MTA), metallothionein B (MTB), glutathione-S-transferase (GST), and glucose-6-phosphate dehydrogenase (G6PD) during cortisol-induced cell injury. MTA, MTB, GST, and G6PD mRNA levels increased after treatment with zinc or cortisol, separately or in combination. Higher mRNA levels of MTA, MTB, GST, and G6PD were detected when cells were treated with $100{\mu}M$ $ZnSO_4$ and $1{\mu}M$ cortisol in combination at the same time compared to treatment with zinc or cortisol separately. Cells treated with zinc showed increased intracellular free zinc concentrations, and this response was significantly enhanced in cells treated with cortisol and zinc. In conclusion, zinc treatment inhibited cortisol-induced cytotoxicity and apoptosis through indirect antioxidant action.

Effects of Pranlukast on Ovalbumin Induced Early-Phase Bronchoconstriction in Guinea Pigs (기니픽에서 Ovalbumin으로 유발된 즉시형 기관지 수축반응에 대한 Pranlukast의 효과)

  • Lee, Sin-Hyung;Shim, Jae-Jeong;Kim, Kyung-Kyu;Jeong, Hye-Cheol;Kwon, Young-Hwan;Kim, Je-Hyeong;Lee, Sung-Yong;Lee, So-Ra;Lee, Sang-Youb;Cho, Jae-Youn;In, Kwang-Ho;Yoo, Se-Hwa;Kang, Kyung-Ho
    • Tuberculosis and Respiratory Diseases
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    • v.46 no.5
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    • pp.697-708
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    • 1999
  • Background : Leukotriene (LT) $C_4$, $D_4$, and $E_4$, the main components of slow-reacting substance of anaphylaxis (SRS-A), have been suggested to play an important role in bronchial asthma such as antigen-induced bronchoconstriction, airway hyperreactivity, and pulmonary eosinophil accumulation. The purpose of this study was to evaluate the effects of treatment with the cysteinyl-LTs (cys-LTs) antagonist, pranlukast on allergen-induced guinea pig asthma model. Methods : Guinea pigs of treatment and placebo groups were sensitized by subcutaneous injection of ovalbumin(OVA) and challenged by inhalation of aerosolized OVA (1% weight/volume OVA). Normal control group did not sensitize with OVA. Oral ingestion of pranlukast and normal saline to the treatment and placebo groups was performed. In the treatment and placebo groups, airway resistance was measured before and after oral ingestion. Serum $LTC_4$ and eosinophilic infiltration of the bronchiolar and peribronchiolar tissues were measured after ingestion in the treatment and placebo groups. Results : Allergen-induced airway constriction developed in 20 (8 in treatment group, 12 in placebo group) among 35 guinea pigs. Airway resistance was significantly decreased at 3 and 6 minutes after OVA challenge in the pranlukast treatment group. In the placebo group, there was no difference of airway resistance between before and after saline ingestion. Serum $LTC_4$ levels showed 348.4 pg/ml in the treatment group, 373.9 pg/ml in the placebo group, and 364.4 pg/ml in the control group. There were no statistically significant difference between treatment and placebo group (p=0.232), and treatment and control group (p=0.501). Eosinophilic infiltrations in the peribronchiolar region per one-microscopic field ($\times$400 high power fields) demonstrated 7.06 in the treatment group, 19.2 in the placebo group, and 4.50 in the control group. There was significant decrement of eosinophilic infiltration in the treatment group which was compared with placebo group (p=0.001). Conclusion : These results demonstrate that pranlukast, a cys-LTs receptor antagonist, can attenuate allergen induced early-phase bronchoconstriction and eosinophilic infiltration in the bronchiolar tissues.

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Effects of white ginseng and red ginseng extract on learning performance and acetylcholinesterase activity inhibition (백삼과 홍삼추출물의 학습수행과 Acetylcholinesterase 억제에 미치는 효과)

  • Lee, Mi-Ra;Sun, Bai-Shen;Gu, Li-Juan;Wang, Chun-Yan;Mo, Eun-Kyoung;Yang, Sun-Ah;Ly, Sun-Young;Sung, Chang-Keun
    • Journal of Ginseng Research
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    • v.32 no.4
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    • pp.341-346
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    • 2008
  • In the present study, we assessed the effects of white ginseng and red ginseng extract on the learning and memory impairments induced by scopolamine. The cognition-enhancing effect of ginseng extracts was investigated using the Morris water maze and Y-maze test. Drug-induced amnesia was induced by treating animals with scopolamine (2 mg/kg, i.p.), an antagonist of muscarinic acetylcholine (ACh) receptor. Tacrine was used a positive control. Ginseng extract (200 mg/kg, p.o.), tacrine (10 mg/kg, p.o.) administration significantly reduced the escape latency during training in the Morris water maze (p<0.05). At the probe trial session, scopolamine significantly increased the escape latency on day 5 in comparison with control (p<0.01). The effect of ginseng extracts on spontaneous alternation in Y-maze was similar to that of scopolamine treated group. In addition, numbers of arm entries were similar in all experimental groups. Moreover, red ginseng extract significantly inhibited acetylcholinesterase activity in the cortex and serum (p<0.05). Brain ACh contents of ginseng extract treated groups increased more than that of scopolamine group, which did not show statistically significant. These results suggest that ginseng extract may be useful for the treatment of cognitive impairment.

Effect of Acute and Chronic Treatment with Risperidone on the Serotonin and Dopamine Receptors in the Rat Brain (Risperidone의 급성 및 만성 투여가 흰쥐 뇌의 Serotonin과 Dopamine 수용체에 미치는 영향)

  • Choi, Yun-Young;Son, Hye-Kyung;Kim, Chang-Yoon;Lee, Chul;Lee, Hee-Kyung;Moon, Dae-Hyuk
    • The Korean Journal of Nuclear Medicine
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    • v.31 no.1
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    • pp.9-18
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    • 1997
  • The therapeutic efficacy of antipsychotic drugs is generally attributed to their ability to block dopamine $D_2$ receptors. Classical $D_2$ antagonists are not effective to treat negative symptoms and produce extrapyramidal side effects On the other hand, atypical antipsychotic agents ameliorate negative symptoms without producing extra-pyramidal side effects, and it is reported to be associated with blockade of serotonin $5-HT_2$ receptors. The purpose of this study was to evaluate the effect of risperidone on neuroreceptors in the rat brain by Quantitative autoradiography method. In acute treatment group, risperidone was injected into Peritoneal cavity of male Wistar rats with dose of 0, 0.1, 0.25, 0.5, 1.0 and 2.0mg/kg in each group(5/group), and they were decapitated after 2 hours. In chronic treatment group, risperidone was injected with dose of 0, 0.1, and 1mg/kg(I.P.) for 21 days and decapitated after 24 hours following last treatment. The effect of risperodone on the binding of [$^3H$]spiperone to $5-HT_2$ and $D_2$ receptors were analysed in 4 discrete regions of the striatum, nucleus accumbens, and frontal cortex by quantitative autoradiography Acute treatment with risperidone reduced cortical $5-HT_2$ specific [$^3H$]spiperone binding to 32% of vehicle-treated control. Subcortical $5-HT_2$ specific [$^3H$]spiperone binding was not affected at all dose groups whereas a significant reduction (57%) in $D_2$ specific [$^3H$]spiperone binding was observed in risperidone treated group at doses of 1-2mg/kg. Chronic treatment with risperidone produced a decrease in the maximal number of cortical $5-HT_2$ receptors to 51% and 46% of control in 0.1mg/kg & 1mg/kg treated group respectively. In conclusion, risperidone is a cortical serotonin receptor antagonist with relatively weak antagonistic action on dopamine receptors. These effects oil neuroreceptors may explain the therapeutic effect of risperidone as a atypical antipsychotic agents.

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Effect of Platelet-Activating Factor on Cyclic Nucleotide Level in Rat Uterine tissue during Preimplantation Period (흰쥐의 임신초기에 있어서 자궁 조직중 Cyclic Nucleotide의 변화 및 Platelet-Activating Factor의 영향에 관한 연구)

  • Park, Kyoung-Sik;Kwun, Jong-Kuk
    • Clinical and Experimental Reproductive Medicine
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    • v.18 no.2
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    • pp.133-142
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    • 1991
  • This study was carried out to observe the change in uterine cyclic nucleotide level and the effect of PAF on cyclic nucleotides in uterine tissue in early pregnany in order to understand reciprocal relation ship between PAF and cyclic nucleotides in pregnancy in the rat. The test groups were injected intramuscularly with $1{\mu}g$ of PAF or 1.25mg of BN-52021 on day 0, 1, 2, 3, 4 and 5 of pregnancy. The level of cyclic nucleotide in removed uterine tissue was assayed by using cyclic nucleotides test kits. The results showed that the cyclic AMP content in uterine tissue of non-pregnant at pro-oestrus rat was $2.91{\pm}0.33$ pmol/mg protein which was lower than those of pregnant rat. The cyclic GMP content in uterine tissue of non-pregnant rat was $0.39{\pm}0.20$ pmol/mg pro-tein which was also lower than those of pregnant rats. The maximum level in cAMP was $5.92{\pm}1.72$ pmol/mg protein on day 3 and cGMP, $1.03{\pm}0.22$ pmol/mg protein on day 4. On each day of pregnancy, PAF induced the increased cAMP level ompared with that of intact rat. That was significant on day 0, 2 and 4 of pregnancy, p<0.05, on the other hand PAF receptor antagonist, BN-52021 ecreased cAMP level in uterine tisssue. PAF as well as BN-52021 had not an consistent effect on changes in cGMP level. These results suggest that cyclic nucleotide levels in uterine tissue ware increased during early pregnancy and PAF influences cAMP level in uterine rather than cGMP level during peri-implantation period, accordingly demonstrating a possible involvement of PAF in the regulation of implantation-related events through cAMP-mediated process.

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