• Title/Summary/Keyword: Pretreatment effect

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Vasorelaxant and hypotensive effects of trazodone in Guinea pig (기니픽에서 trazodone의 혈관 이완 및 혈압 하강 효과)

  • Kim, Shang-Jin;Kang, Hyung-Sub;Kim, Jin-Shang
    • Korean Journal of Veterinary Research
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    • v.45 no.4
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    • pp.485-493
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    • 2005
  • We studied the effects of trazodone on arterial blood pressure in anesthesized guinea pigs, and on vascular responses in isolated thoracic aorta. Trazodone produced a concentration-dependent relaxation in phenylephrine-precontracted endothelium intact (+E) rings, but not in a KCl-precontracted aortic rings. These relaxant effects of trazodone on +E rings were significantly greater than those on denuded (-E) rings. The trazodone-induced relaxation was suppressed by glibenclamide and tetrabutylammonium, but not by N(G)-nitro-L-arginine (L-NNA), N(omega)-nitro-L-arginine methyl ester (L-NAME), methylene blue (MB), nifedipine, indomethacin, 2-nitro-4-carboxyphenyl-n,n-diphenylcarbamate (NCDC) and clotrimazole. In vivo, infusion of trazodone elicited a significant decrease in arterial blood pressure. Trazodone-induced blood pressure lowering was markedly inhibited by intravenous pretreatment of prazosin but not by pretreatment of saponin, L-NNA, L-NAME, MB, nifedipine, glibenclamide, clotrimazole and NCDC. In addition, trazodone produced an increase in twitch force of isolated papillary muscle and left ventricular pressure of perfused heart. These findings suggest that the endothelium-independent vasorelaxant effect of trazodone may be explained by activation of $Ca^{2+}$-activated and ATP-sensitive $K^+$ channels, and the hypotensive effect of trazodone is not associated with cardiac contraction.

Effect of Thermal Pretreatment on the Functional Constituents of Waxy Corn (Zea mays L.)

  • Kim, Eun-Ok;Yu, Myong-Hwa;Lee, Ki-Teak;Yun, Kyoung-Seob;Choi, Sang-Won
    • Food Science and Biotechnology
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    • v.18 no.6
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    • pp.1336-1341
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    • 2009
  • Quantitative changes in functional constituents of waxy corn (Zea mays L.) by 5 different thermal pretreatments, including roasting, steaming, microwave, puffing, and extruding, were determined and compared with those of the raw waxy corn. There were no significant differences in fatty acid compositions among the corn treated with 5 thermal treatments. Levels of $\alpha$- and $\gamma$-tocopherols, soluble amino acids, and phytosterols decreased by thermal treatments, while those of p-coumaric and ferulic acids considerably increased by thermal treatments. In particular, the contents of tocopherols and phytosterols, and souble amino acid decreased significant in the steaming and puffing processes, respectively, whereas those of 2 free cinnamic acids increased significantly in the steaming and puffing processes. The extruding process showed smaller quantitative changes in tocopherols, phytosterols, and hydroxycinnamic acid derivatives compared to other heat pretreatments. These results suggest that the extruding process have a positive effect on valuable phytochemicals in waxy corn.

Effect of Low Dose Mutagens on Adoptive Response and Plasma Membrane Glycoconjugates in Sarcoma 180 Cells

  • Lee, Jong Hwa;Choi, Eun Sili;Oh, Kyu Seon;Lee, Dong Wook;Chang, Jeong Hyun;Um, Kyung Il
    • Animal cells and systems
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    • v.4 no.3
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    • pp.293-297
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    • 2000
  • The present investigation was performed to elucidate the effect of pretreatment with low dose ultraviolet radiation (UV) and ethyl methanesulfonate (EMS) on cell survival by trypan blue dye exclusion method and plasma membrane glycoconjugates by lectin-cytochemistry in sarcoma 180 (S180) cells. Pretreatment with 2 J/$m^2$ UV or 2 mM EMS increased the percentage of survival of cells subsequently treated with high dose UV (10 or 20 J/$m^2$) or EMS (10 or 20 mM), respectively. Staining intensity of concanavalin A (Con A) of the cells pretreated with 2J/$m^2$ UV or 2 mM EMS and subsequently treated with 10 or 20 mM EMS was stronger than that of the cellstreated with 10 or 20 mM EMS. These results suggest that there is an adaptive response on cell survival to EMS or UV in S180 cells. And the results show a change in mannose-containing glycoconjugates of plasma membrane in S180 cells pretreated with EMS or UV and subsequently treated with EMS.

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Benzodiazepine System is Involved in Hyperalgesia in Rats Induced by the Exposure to Extremely Low Frequency Magnetic Fields

  • Jeong Ji Hoon;Choi Kyung Bum;Moon Nam Ju;Park Eon Sub;Sohn Uy Dong
    • Archives of Pharmacal Research
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    • v.28 no.2
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    • pp.238-242
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    • 2005
  • Many reports demonstrate that extremely low frequency magnetic fields (ELF MFs, 60 Hz) may be involved in hyperalgesia. In a previous investigation, we suggested that MFs may produce hyperalgesia and such a response may be regulated by the benzodiazepine system. In order to further confirm this effect of MFs, we used diazepam and/or flumazenil with MFs exposure. When testing the pain threshold of rats using hot plate tests, MFs or diazepam ($0.5\;{\mu}g$, i.c.v.; a benzodiazepine receptor agonist) induced hyperalgesic effects with the reduction of latency. These effects were blocked by a pretreatment of flumazenil (1.5 mg/kg, i.p.; a benzodiazepine receptor antagonist). When the rats were exposed simultaneously to MFs and diazepam, the latency tended to decrease without statistical significance. The induction of hyperalgesia by co-exposure to MFs and diazepam was also blocked by flumazenil. However, the pretreatment of GABA receptor antagonists such as bicuculline ($0.1\;{\mu}g$, i.c.v.; a $GABA_A$ antagonist) or phaclofen ($10\;{\mu}g$, i.c.v.; a $GABA_B$ antagonist) did not antagonize the hyperalgesic effect of MFs. These results suggest that the benzodiazepine system may be involved in MFs-induced hyperalgesia.

Effect of Korean Ginseng on the Isolated Rabbit Corpus Cavernosal Smooth Muscle (고려인삼의 토끼 음경 해면체 평활근에 대한 작용)

  • Choi, Young-Deuk;Xin, Zhong-Cheng;Choi, Hyung-Ki
    • Journal of Ginseng Research
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    • v.20 no.2
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    • pp.133-138
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    • 1996
  • Rabbit corpus cavernosal smooth muscle strips submaximally precontracted with phenylephrine (5$\times$$10^6$ M) and treated with increasing concentrations of Korean ginseng (1, 5, 10, 20, 30, 40 mg/ml) showed tension decrease concentration-dependently (1 mg/ml: 1.7%, 5 mg/ml: 10.2%, 10 mg/ml: 22.7%, 20 mg/ml: 44.0%, 30 mg/ml: 65.2%, 40 mg/ml: 95.6%). Relaxations to Korean ginseng were inhibited significantly by endothelial disruption, by pretreatment with methylene blue, pyrogallol, L-NNA and atropine. Pretreatment of the muscle strips with ginseng caused concentration-related inhibition of a phenylephrine induced contraction, and in calcium-free high potassium depolarizing solution, decreased basal tension as well as inhibited contraction induced by Caclr. Korean ginseng also produced the reduction of responses to depolarizing medium(50, 40, 60 mM KCI). With these results we can confirm the relaxation effect of ginseng at a dose dependent on the cavernosal smooth muscle and suggest that its action is mediated by multiple action mechanisms that include increasing the release of nitric oxide from the corporal sinusoids. Increasing intracellular calcium sequestration, and a hyperpolarizating action.

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Effect of Ginseng on the Alcohol Metabolism in Alcohol Treated Rat (알톨 대사에 미치는 인삼의 영향)

  • Huh, Keun;Choi, Chong-Won
    • YAKHAK HOEJI
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    • v.28 no.1
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    • pp.49-51
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    • 1984
  • After pretreatment with ginseng followed by induction of acute intoxication of alcohol, the activities of alcohol dehydrogenase (ADH), microsomal ethanol-oxidizing system (MEOS) and aldehyde dehydrogenase(Ald DH) increased respectively compared to the groups treated with alcohol alone. In case that ginseng was given to rats fed with 5% alcohol instead of water for 60 days, the activities of ADH and MEOS increased compared to the groups treated. On the contrary, the activity of Ald DH in mitochondrial fraction decreased to an extent of about 35% in chronic alcoholism, but after pretreatment of ginseng the activity was restored to the control level. On the other hand, the catalase activity was not significantly affected by either treatment. Ginseng butanol fraction significantly increased the serum isocitrate dehydrogenase activity which is inhibited by alcohol-treated in rat. Alcohol-induced lactate dehydrogenase activity was decreased to control level in liver by ginseng treatment. And the serum level of lactic acid also decreased by ginseng treatment in alcohol-intoxicated rat. Ginseng butanol fraction markedly decreased the xanthine oxidase activity in the ethanol-treated rat liver. It was also observed that ginseng reduced the blood concentration of uric acid on experimentally reduced hyperuricemia by alcohol treatment. Uricase activity was not affected by either treatment. Ginseng butanol fraction decreased the hepatic aniline hydroxylase activity which was induced by alcohol-treated rat. These results suggest that the treatment with ginseng can be promoted the recovery from alcohol intoxication and some therapeutic effect on alcoholinduced metabolic disease.

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EFFECT OF GLYCYRRHETINIC ACID ON PYRIDINE TOXICITY IN MOUSE

  • Keun Huh;Lee, Sang-Il;Park, Jong-Min;Chung, Jung-Rok
    • Toxicological Research
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    • v.2 no.1
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    • pp.31-36
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    • 1986
  • The present work was undertaken to investigate the effect of glycyrrhetinic acid on pyridine toxicity. When glycyrrhetinic acid was pretreated, pyridine-induced CNS depression and mortality were decreased. A striking enhancement of serum transaminase activities after pyridine administration was markedly decreased by glycyrrhetinic acid pretreatment. It was also observed that the hepatic microsomal aniline hydroxylase activity, which is concerned with pyridine metabolism, was significantly increased in glycyrrhetinic acid pretreated mice.

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Effect of ketoconazole on the Pharcokinetics of Paclitaxel in Rats

  • Choi, Jun-Shik;Li, Xiuguo;Lee, Jin-Hwan
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.306.1-306.1
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    • 2003
  • The purpose of this study was to investigate the effect of ketoconazole(20mg/kg) on the pharmacokinetic parameters and the bioavailability of paclitaxel(40mg/kg) orally coadministered in rats. The plasma concentration of paclitaxel in combination with ketoconazole was increased significantly (coadministration p<0.05, pretreatment p<0.01) compared to that of control. (omitted)

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Protective Effects of 2-(Allylthio)pyrazine on Retinoyl Palmitate- and Pyridine-Potentiated Carbon tetrachloride- induced Hepatotoxicity: Effect on ${\Phi}x$-174 DNA Strand Breakage (비타민 A 및 피리딘으로 유발된 사염화탄소 유발성 간독성에 대한 2-(알릴티오)피라진의 보호효과: ${\Phi}$x-174 DNA 손상에 미치는 효과)

  • Kim, Sang-Geon;Cho, Joo-Youn;Choi, Sung-Hee;Kim, Nak-Doo
    • YAKHAK HOEJI
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    • v.40 no.6
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    • pp.727-733
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    • 1996
  • 2-(Allylthio)pyrazine is effective in selectively suppressing constitutive and inducible expression of cytochrome P450 2E1. The effect of 2-(allylthio)pyrazine against potentiat ed chemical injury was studied in rats. Vitamin-A pretreatment of rats substantially increased carbon tetrachloride hepatotoxicity, as supported by an ~4-fold increase in serum alanine aminotransferase (ALT) activity. Concomitant pretreatment of rats with 2-(allylthio)pyrazine at the daily dose of 200mg/kg resulted in a 76% decrease in vitamin-A-potentiated hepatotoxicity, which supported the possibility that 2-(allylthio)pyrazine protects the liver against chemical-induced hepatic injury by the mechanism associated with Kupffer cell inactivation. Pyridine pretreatment caused substantial enhancement in carbon tetrachloride hepatotoxicity. 2-(Allylthio)pyrazine treatment of rats reduced the pyridine-potentiated toxicity in a dose-dependent manner. Animals treated with both pyridine and 2-(allylthio)pyrazine prior to intoxicating dose of CCl$_4$ resulted in 85% and 47% decreases in pyridine-increased triglycerides and cholesterol levels in the liver. The protective effect of 2-(allylthio)pyrazine on the DNA strand breakage induced by benzenetriol was assessed by measuring the conversion of supercoiled ${\Phi}x$-174 DNA to the open relaxed form. 2-(Allylthio)pyrazine blocked the benzenetriol-induced conversion of supercoiled DNA to open circular form in a dose-dependent manner. The presence of 2-(allylthio)pyrazine at the doses from I to 10mM in the incubation mixture containing 5 ${\mu}$M benzenetriol completely protected benzenetriol-induced DNA strand breakage with the EC50 for the 2-(allylthio)pyrazine blocking being noted as ~220 ${\mu}$M, whereas allyl disulfide exerted protecting effect at relatively high concentrations (i.e. ~850 ${\mu}$M), suggesting that 2-(allylthio)pyrazine effectively scavenges the reactive oxygen species. These results provide evidence that 2-(allylthio)pyrazine blocks vitamin A- or pyridine-potentiated CCl$_4$ hepatotoxicity and that the agent is active in protecting DNA by scavenging the reactive oxygen species.

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Anti-inflammatory Effects of Goihwa-san Water Extract via NF-κB Inhibition (괴화산(槐花散)의 NF-κB 기전을 통한 항염증 효과 연구)

  • Hyun Hee Cho;Ji Young Choi;Min Hwangbo;Seon Young Jee
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.36 no.1
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    • pp.21-39
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    • 2023
  • Objectives : The purpose of this study was to investigate the anti-inflammatory effect of Goihwa-san water extract(GHS) in vitro & in vivo. Methods : In vitro, we evaluated the anti-inflammatory effect of GHS by comparing the Raw 264.7 cells with 10, 30, 100, 300㎍/㎖ of GHS for 1 hour before Lipopolysaccharide(LPS) to the single LPS treated group. We examined the relative cell viability by MTT assay and the relative level of LPS, Loxoribine(LOX), Peptidoglycan(PGN), Flagellin(FLA)-induced NO production by using Griess reagent and measured relative iNOS protein level and COX-2 protein level by using western blot and Image analyzing system. We measured the production of TNF-α, IL-1β, and IL-6 by each ELISA kits and then measured the relative levels of IκBα, p-IκBα in whole-cell lysate fraction and NF-κB in nuclear fraction by using western blot and Image analyzing system. In vivo, we induced the paw edema by subcutaneous injection of 100㎕/rat CA and measured the swelling volume of paw by using a plethysmometer and then measured the relative iNOS protein level by using western blot. Results : As a result, in vitro, LPS, PGN-induced NO production was significantly inhibited by pretreatment with GHS. GHS reduced LPS, PGN-induced iNOS expression, PGN-induced COX-2 expression and LPS-induced production of cytokine(TNF-α, IL-1β, IL-6). Expression of IκBα was increased by pretreatment with GHS 100㎍/㎖. And the expression of p-IκBα and NF-κB were decreased by pretreatment with GHS 100㎍/㎖. In vivo, CA-induced inflammation rat model was used for the evaluation of the anti-inflammatory effect of GHS. 0.3 or 1.0g/kg of GHS significantly reduced the increases of paw swelling and iNOS expression in paw tissues. Conclusions : These results show that GHS can decrease inflammatory response via inhibition of the NF-κB pathway in vitro. And in vivo, the anti-inflammatory effect suggest the clinical basis of GHS for the treatment of inflammatory diseases.