• Title/Summary/Keyword: adenosine 5'-monophosphate inhibition

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Salmonella sp. 의 신속한 동정을 위한 증진배양의 개선에 관한 연구

  • Kim, Kee-Tae;Kim, Tae-Ue;Yook, Soon-Hak;Pek, Un-Hua
    • Microbiology and Biotechnology Letters
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    • v.24 no.6
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    • pp.647-651
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    • 1996
  • The development of an enrichment method for the rapid and effective identification of Salmonella spp. in sewage or food was studied. As a growth factor for Salmonella, 10 mM cyclic adenosine monophosphate (cAMP) in trypticase soy broth with 0.6% yeast extract (TSBYE) increased cell number five-folds and 0.6% yeast extract in selenite broth increased cell number ten-folds of control. Bile salts in selenite broth was tested for the selection of S. enteritidis in a mixture with Staphylococcus aureus, Pseudomonas aeruginosa, Lactobacillus plantarum and Escherichia coli. The latter four strains were effectively inhibited at 0.1% bile salt. A two-step culture method was used to enrich Salmonella spp.; a primary-enrichment and secondary- enrichment culture. At a primary-enrichment step, selenite broth with 0.6% yeast extract and 10 mM cAMP was used, and at a secondary-enrichment step, 0.1% bile salt was additionally used. Culture times of a primary- enrichment and a secondary-enrichment step were 8 hr and 6 hr, respectively. In this procedure, cell number increased from 10$^{0.3}$ to 10$^{8.5}$ with inhibition of other strains within 14 hr. In the case of an initial cell concentrarion as low as 10$^{-2}$ cfu/ml, a cell number increased to 10$^{7}$ cfu/ml by using a 10 hr primary-enrichment and 6 hr secondary-enrichment procedure.

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Anti-thrombotic effects of ginsenoside Rk3 by regulating cAMP and PI3K/MAPK pathway on human platelets

  • Hyuk-Woo Kwon ;Jung-Hae Shin ;Man Hee Rhee ;Chang-Eun Park ;Dong-Ha Lee
    • Journal of Ginseng Research
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    • v.47 no.6
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    • pp.706-713
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    • 2023
  • Background and objective: The ability to inhibit aggregation has been demonstrated with synthetically derived ginsenoside compounds G-Rp (1, 3, and 4) and ginsenosides naturally found in Panax ginseng 20(S)-Rg3, Rg6, F4, and Ro. Among these compounds, Rk3 (G-Rk3) from Panax ginseng needs to be further explored in order to reveal the mechanisms of action during inhibition. Methodology: Our study focused to investigate the action of G-Rk3 on agonist-stimulated human platelet aggregation, inhibition of platelet signaling molecules such as fibrinogen binding with integrin αIIbβ3 using flow cytometry, intracellular calcium mobilization, dense granule secretion, and thromboxane B2 secretion. In addition, we checked the regulation of phosphorylation on PI3K/MAPK pathway, and thrombin-induced clot retraction was also observed in platelets rich plasma. Key Results: G-Rk3 significantly increased amounts of cyclic adenosine monophosphate (cAMP) and led to significant phosphorylation of cAMP-dependent kinase substrates vasodilator-stimulated phosphoprotein (VASP) and inositol 1,4,5-trisphosphate receptor (IP3R). In the presence of G-Rk3, dense tubular system Ca2+ was inhibited, and platelet activity was lowered by inactivating the integrin αIIb/β3 and reducing the binding of fibrinogen. Furthermore, the effect of G-Rk3 extended to the inhibition of MAPK and PI3K/Akt phosphorylation resulting in the reduced secretion of intracellular granules and reduced production of TXA2. Lastly, G-Rk3 inhibited platelet aggregation and thrombus formation via fibrin clot. Conclusions and implications: These results suggest that when dealing with cardiovascular diseases brought upon by faulty aggregation among platelets or through the formation of a thrombus, the G-Rk3 compound can play a role as an effective prophylactic or therapeutic agent.

Ginsenoside Rk3 suppresses U46619-induced human platelets aggregation through regulation of cAMP and PI3K/Akt pathway (U46619 유도의 사람 혈소판에서 cAMP 및 P I3K/Akt 경로의 조절을 통한 Ginsenoside Rk3의 응집억제 효과)

  • Dong-Ha Lee
    • Journal of Applied Biological Chemistry
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    • v.66
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    • pp.221-226
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    • 2023
  • Proper activation and aggregation of platelets are necessary, but excessive or abnormal aggregation can lead to cardiovascular diseases such as stroke, thrombosis, and atherosclerosis. Therefore, identifying a substance that can regulate or inhibit platelet aggregation is important for preventing and treating these diseases. Several studies have shown that certain ginsenoside compounds in Panax ginseng can inhibit platelet aggregation. Among these compounds, Rk3 (G-Rk3) from Panax ginseng needs to be further explored in order to reveal the mechanisms of action during inhibition. G-Rk3 significantly increased amounts of cyclic adenosine monophosphate (cAMP) and led to significant phosphorylation of cAMP-dependent kinase substrates vasodilator-stimulated phosphoprotein and inositol 1,4,5-trisphosphate receptor. Furthermore, the effect of G-Rk3 extended to the inhibition of PI3K/Akt phosphorylation resulting in the reduced secretion of intracellular granules. Ultimately, G-Rk3 effectively inhibited platelet aggregation. Therefore, we suggest G-Rk3's potential as a prophylactic or therapeutic agent for cardiovascular diseases caused by faulty platelet aggregation.

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Studies on Enzymatic Characteristic′s of Adenylate Kinase from Baker′s Yeast (제빵효모 Adenylate Kinase의 효소학적 특성에 관하여)

  • ;Takahisa Ohta;Hiroshi Sakai
    • Microbiology and Biotechnology Letters
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    • v.12 no.4
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    • pp.277-283
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    • 1984
  • In the forward reaction (ADP formation) of the adenylate kinase from baker's yeast, dissociation constants from binary complexes are higher by a factor of about 4 times then those from at ternary complexes. In the reverse reaction, dissociation constants from the binary complexes are 2 times higher then those from the ternary complexes. The enzyme showed activities against various nucleotide triphospate in following orders; ATP 100, UTP 18, ITP 9 and GTP 5, of the necleotide monophosphate. only dAMP showed 33% activity of that AMP as phosphate acceptor. Divalent cations were required in enzyme reaction in following orders; $Mg^{2+}$ 100, Co$^{2+}$ 57, Mn$^{2+}$ 54, $Ca^{2+}$ 51, Ni$^{2+}$ 10 and Sn$^{2+}$ 6. AMP, as a substrate inhibitor, competitively inhibited the adenylate kinase at pH 7.2 or 8.0. Inhibition constants of the enzyme showed greater dependence on the pH of the reaction mixture, which was the lower Ki values under higher pH. Adenosine pentaphospho adenosine was competive inhibitor to the enzyme against all substrate, and it showed the same Ki values, 2.9mM. Further, PEP was competive inhibitor with respect to AMP and non-competive inhibitor with respect to MgATP. Adenylate kinase from bakers yeast was similar to mitochondrial type of animal in the contents of aianine, leucine and asparagine or asparatic acid differing from muscle type enzyme. Based on the results and observation, characteristic of yeast adenylate kinase resembled the adenylate kinase of mitochondrial type from animals. Further, difference of characteristics in adenylate kinasa depending upon the workers might be due to the difference of strain used.

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Relaxation Patterns of Human Gastric Corporal Smooth Muscle by Cyclic Nucleotides Producing Agents

  • Kim, Young-Chul;Choi, Woong;Sung, Ro-Hyun;Kim, Heon;You, Ra-Young;Park, Seon-Mee;Youn, Sei-Jin;Kim, Mi-Jung;Song, Young-Jin;Xu, Wen-Xie;Lee, Sang-Jin;Yun, Hyo-Yung
    • The Korean Journal of Physiology and Pharmacology
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    • v.13 no.6
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    • pp.503-510
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    • 2009
  • To elucidate the mechanism of cyclic nucleotides, such as adenosine 3',5'-cyclic monophosphate (cAMP) and guanosine 3',5'-cyclic monophosphate (cGMP), in the regulation of human gastric motility, we examined the effects of forskolin (FSK), isoproterenol (ISO) and sodium nitroprusside (SNP) on the spontaneous, high $K^+$ and acetylcholine (ACh)-induced contractions of corporal circular smooth muscle in human stomach. Gastric circular smooth muscle showed regular spontaneous contraction, and FSK, ISO and SNP inhibited its phasic contraction and basal tone in a concentration-dependent manner. High $K^+$ (50 mM) produced sustained tonic contraction, and ACh $(10\;{\mu}M)$ produced initial transient contraction followed by later sustained tonic contraction with superimposed phasic contractions. FSK, ISO and SNP inhibited high $K^+$-induced tonic contraction and also ACh-induced phasic and tonic contraction in a reversible manner. Nifedipine $(1\;{\mu}M)$, inhibitor of voltage-dependent L-type calcium current $(VDCC_L)$, almost abolished ACh-induced phasic contractions. These findings suggest that FSK, ISO and SNP, which are known cyclic nucleotide stimulators, inhibit smooth muscle contraction in human stomach partly via inhibition of $VDCC_L$.

Agarwood Inhibits Histamine Release from Rat Mast Cells and Reduces Scratching Behavior in Mice -Effect of Agarwood on Histamine Release and Scratching Behavior-

  • Inoue, Eiji;Shimizu, Yasuharu;Masui, Ryo;Tsubonoya, Tomoe;Hayakawa, Tomomi;Sudoh, Keiichi
    • Journal of Pharmacopuncture
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    • v.19 no.3
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    • pp.239-245
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    • 2016
  • Objectives: This study was conducted to clarify the effects of agarwood on histamine release from mast cells in rats and on the scratching behaviors in mice. Methods: Histamine release from rat mast cells induced by compound 48/80 or concanavalin A (Con A) and compound 48/80-induced scratching behavior in mice were examined to investigate the effects of agarwood. The hyaluronidase activity and the 3',5'-cyclic adenosine monophosphate (cAMP) levels in mast cells were examined to investigate the mechanisms for the inhibition of histamine release. The correlation between the inhibitory effects of agarwood on histamine release and the content of its typical ingredients, a 2-(2-phenylethyl)chromone derivatives, was analyzed using thin-layer chromatography. Results: Agarwood showed an inhibitory effect on mast-cell histamine release induced by compound 48/80 or Con A without any effect on hyaluronidase activity; this effect involves an increase in the cAMP levels in mast cells. Oral administration of agarwood showed an inhibitory effect on compound 48/80-induced scratching behavior in mice. The inhibitory effects of agarwood on histamine release were quite different, depending on the area where the agarwood was produced, its quality, and its market price. No correlation was found between the inhibitory effects of agarwood on histamine release and the typical ingredients of agarwood, which are 2-(2-phenylethyl)chromone derivatives. Conclusion: These results show that agarwood inhibits histamine release from mast cells partially through an increase in the cAMP levels in cells. We suggest that some active ingredients of agarwood must be effective on oral intake and that agarwood can be used to treat patients with a number of conditions, including urticaria, atopic dermatitis, and bronchial asthma, in which an increase in histamine release occurs. Differences in the pharmacological effects of this crude drug among markets may provide important information for the quality control of this herbal medicine.

The Changes of Cyclic AMP Content by Opiates in Chronic Haloperidol Treated Mouse Striatum (Haloperidol 장기 투여된 Mouse Striatum에서 cAMP양에 미치는 Opiates의 영향)

  • Kim, Soo-Kyung
    • The Korean Journal of Pharmacology
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    • v.30 no.1
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    • pp.11-18
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    • 1994
  • Cyclic adenosine 3'5'-monophosphate (cyclic AMP) has been frequently accepted as an intracellular messenger for receptor-mediated action of opioids. In this experiment, it was designed to determine the interaction of dopaminergic and opioidergic system in the mouse striatum in normal and chronic haloperidol treated groups. Haloperidol 750ug/kg I.P. for 10 days was performed for dopamine denervation. The morphine, DAGO, DPDPE, and U5O,488H inhibited the increase of haloperidol-induced cyclic AMP content in chronic haloperidol treated mouse striatum. The inhibition of DAGO and DPDPE showed significant increase compared to normal mouse striatum. Naloxone showed antagonistic effect on the morphine and U5O,488H in chronic haloperidol treated group, and showed antagonistic effect on morphine, DAGO, DPDPE, and U5O, 488H in normal mouse striatum. These findings support that there is a functional interrelationship of dopaminergic and opioidergic pathway in the striatum. This result provides an evidence that following destruction of striatal dopaminergic neuron, there are some changes of cAMP content on the ${\mu},\;{\gamma},\;and\;{\kappa}$ opioid receptor, but the ${\kappa}$ opioid receptor still has its function.

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Effects of Essential Oils Extracted from Cnidii Rhizoma on Differentiation and Adipogenesis in 3T3-L1 Adiopocytes (천궁(川芎)의 정유 추출물이 3T3-L1 세포의 분화 및 지방 생성에 미치는 영향)

  • Choi, Soo-Min;Kim, So-Young;Park, Na-Ri;Kim, Jung-Min;Yang, Doo-Hwa;Woo, Chang-Hoon;Kim, Mi-Ryeo;An, Hee-Duk
    • Journal of Korean Medicine Rehabilitation
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    • v.28 no.3
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    • pp.13-25
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    • 2018
  • Objectives We investigated anti-obesity effects of essential oils extracted from Cnidii Rhizoma (CR) in immature adipocytes to magnify it's clinical therapeutic usage. Methods Essential oil of CR was extracted with ethyl acetate or petroleum ether and through steam distillation, respectively. Oil red-O staining for monitoring its inhibition effect on adipogenesis and differentiation in murine 3T3-L1 adipocytes and 3-(4,5-methylthiazol-2-yl)-2,5-diphenyletetra zolium bromide (MTT) assay for cell safety were done. Also phospho-adenosine monophosphate (AMP)-activted protein kinase (P-AMPK), AMP-activated protein kinase, phospho-acetyl-CoA carboxylase (P-ACC), acetyl-CoA carboxylase, peroxisome proliferator-activated receptor-${\alpha}$ (PPAR-${\alpha}$), peroxisome proliferator-activated receptor-${\gamma}$ (PPAR-${\gamma}$) and CCAAT/enhancer binding protein ${\alpha}$ (C/EBP-${\alpha}$) expressions as obesity-related factors were measured by western blot analysis. Results Protein expressions of P-AMPK, P-ACC and PPAR-${\alpha}$ were increased in essential oils-treated adipocytes compared to those of control group, respectively. Furthermore, protein expressions of PPAR-${\gamma}$ and C/EBP-${\alpha}$ were decreased in essential oils-treated adipocytes compared to those of control group, respectively. Conclusions These results demonstrate that essential oils of CR inhibit adipogenesis and differentiation. Also they promote the oxidation of fatty acids in adipocytes. Thus, results suggest that essential oils of CR could be used as a valuable material for anti-obesity therapeutics via control of lipid metabolism.