• Title/Summary/Keyword: Thromboxane A2 synthetase

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Thromboxane A2 Synthetase Inhibitor Plus Low Dose Aspirin : Can It Be a Salvage Treatment in Acute Stroke Beyond Thrombolytic Time Window

  • An, Gyu-Hwan;Sim, Sook-Young;Jwa, Cheol-Su;Kim, Gang-Hyeon;Lee, Jong-Yun;Kang, Jae-Kyu
    • Journal of Korean Neurosurgical Society
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    • v.50 no.1
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    • pp.1-5
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    • 2011
  • Objective : There is no proven regimen to reduce the severity of stroke in patients with acute cerebral infarction presenting beyond the thrombolytic time window. Ozagrel sodium, a selective thromboxane A2 synthetase inhibitor, has been known to suppress the development of infarction. The antiplatelet effect is improved when aspirin is used together with a thromboxane synthetase inhibitor. Methods : Patients with non-cardiogenic acute ischemic stroke who were not eligible for thrombolysis were randomly assigned to two groups; one group received ozagrel sodium plus 100 mg of aspirin (group 1, n=43) and the other 100 mg of aspirin alone (group 2, n=43). Demographic data, cardiovascular risk factors, initial stroke severity [National Institute of Health Stroke Scale (NIHSS) and motor strength scale] and stroke subtypes were analyzed in each group. Clinical outcomes were analyzed by NIHSS and motor strength scale at 14 days after the onset of stroke. Results : There were no significant differences in the mean age, gender proportion, the prevalence of cardiovascular risk factors, stroke subtypes, and baseline neurological severity between the two groups. However, the clinical outcome for group 1 was much better at 14 days after the onset of stroke compared to group 2 (NIHSS score, p=0.007, Motor strength scale score, p<0.001). There was one case of hemorrhagic transformation in group 1, but there was no statistically significant difference in bleeding tendency between two groups. Conclusion : In this preliminary study, thromboxane A2 synthetase inhibitor plus a low dose of aspirin seems to be safe and has a favorable outcome compared to aspirin alone in patients with acute ischemic stroke who presented beyond the thrombolytic time window.

Application of thromboxane synthetase inhibitor (Ozagrel HCl) in feline infectious peritonitis (고양이 전염성 복막염에 thromboxane synthetase inhibitor (Ozagrel HCl)의 적용)

  • Kim, Tae-Sin;Lee, Sun-Hee;Lim, Soo-Jung;Park, Hyung-Jin;Song, Eun-Sik;Jung, Dae-Wook;Kim, Duck-Hwan;Song, Kun-Ho
    • Korean Journal of Veterinary Research
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    • v.50 no.1
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    • pp.63-69
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    • 2010
  • A Persian chinchila (2 years old, intact female) and a Korean domestic shorthaired cat (3 months, intact male) were referred to the Veterinary Medical Teaching Hospital of Chungnam National University with tachypnea. The two cats were diagnosed as feline infectious peritonitis (FIP) by blood and blood chemical examination, radiographic examination, RT-PCR and electrophoresis analysis of pleural effusion. Thromboxane synthetase inhibitor (Ozagrel HCl, 5 mg/kg, twice a day) was administered to the Persian chinchila and Korean domestic shorthair for 13 days and 16 days, respectively. Pleural effusion disappeared after treatment with Ozagrel HCl. Further study is needed to establish a new application protocol of Ozagrel HCl for FIP cases.

The Effect of Eicosanoid Analogues on the Change to Blood Pressure in Rat (Eicosanoid 유도체가 흰쥐 혈압 변화에 미치는 영향)

  • 윤재순;윤연숙;신정희;최현진;최진아
    • Biomolecules & Therapeutics
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    • v.3 no.2
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    • pp.104-110
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    • 1995
  • Arachidonic acid (AA, C20 : 4, $\omega$-6) and eicosapentanoic acid (EPA,C20 : 5, $\omega$-3), which are polyunsaturated fatty acids forming eicosanoids, were tested for their effects on blood pressure in Wistar rats and SHR. AA is the most important precursor for the biosynthesis of eicosanoids which include the prostaglandins, prostacyclin (PGI$_2$), thromboxane $A_2$ (TXA$_2$) and the leukotriens. TXA$_2$is a potent vasoconstrictor and a powerful inducer of platelet aggregation causing myocardial infarction and hypertention. In contrast, PGI$_2$ induces vasodilation and inhibits platelet aggregation. In this study, AA markedly increased blood pressure, but its effect was antagonized by both EPA, a structural analog of AA, and dazmegrel, a TX synthetase inhibitor. Also, AA enhanced the antihypertensive effects of hydralazine and captopril, and EPA reduced TXA$_2$ production. These results indicate that the hypotensive effects of EPA might be closely related to the decrease in TXA$_2$ biosynthesis due to competitive inhibition by structural similarity of the EPA to the AA, the precursor of TXA$_2$.

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Effect of Ginseng Saponins on the Biosynthesis of Prostaglandins (인삼 사포닌 성분이 프로스타글란딘류 생성에 미치는 영향)

  • 이선희;박찬웅
    • Journal of Ginseng Research
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    • v.13 no.2
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    • pp.202-210
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    • 1989
  • The effects of Ginseng saponins on the in vitro biosynthesis of prostaglandins were examined in order to identify the role of some Ginseng components on the regulation of arachidonic arid metabolism. The productions of prostaglandin $E_2$ (PG$E_2$), $F_2$ (PGF2), thromboxane $B_2$(TX$B_2$) and 6-ketoprostaglandin Fl (6-Keto-PGF1) from [3Hl-arachidonic acid were evaluatpf by radiochromatographic analysis with rabbit kidney microtome, human platelet homogenate and bovine aortic microsome. The amounts of the total prostaglandins produced by cyclooxygenase activity and malondialdehyde from arachidonic acid didn't show significant changes in the presence of Ginseng saponins. Both of panaxadiol and panaxatriol didn't affect the production of PG$E_2$ while the formations of PG$F_2$( and TX$B_2$( were nearkedly reduced and the production of prostacyclin was increased. The formation of TXBE was reduced by ginsenoside $Rb_2$, Rc, and Re, however the production of 6-Keto-PGF1 was increased dose dependently up to 1 mg/ml. Moreover, platelet aggregations induced by arachidonic acid and U46619 (9.11-methanepoxy PG$H_2$), TX$A_2$ mimetics, were also inhibited by three ginsenosides. The effect of G-Re on prostacyclin synthetase was inhibited by tranylcypromine, prostacyclin synthetase inhibitor. These results suggest that Ginseng saponins may not directly act on cyclooxygenase but affect on the divergent pathway from endoperoxide.

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The Effect of Ginseng Saponins on the Biosynthesis of Prostaglandins (인삼 Saponin이 Prostaglandin 대사에 미치는 영향)

  • Park C.W.;Lee S.H.
    • Proceedings of the Ginseng society Conference
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    • 1988.08a
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    • pp.77-80
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    • 1988
  • The effects of ginseng saponins and some phenolic acids on the in vitro biosynthesis of prostaglandins was examined in order to identify the role of some ginseng components on the regulaion of arachidonic acid metabolism. The productions of prostaglandin $E_2(PGE_2).$ prostaglandin $F_2{\alpha}(PGF_2{\alpha}).$ thromboxane $B_2(TxB_2)$ and 6-keto-prostaglandin $F_1{\alpha}(6-keto-PGF_1{\alpha})$ from $[^3H]-arachidonic$ acid were evaluated with rabbit kidney microsome. human platelet homogenate and bovine aortic microsome. The amounts of the total cyclooxy-genase products from arachidonic acid did't show significant changes in the presence of ginseng saponins. Panaxadiol. panaxatriol and all of the ginsenosides used in these experiments reduced the formation of $TxB_2.$ while increased the $6-keto-PGF_1{\alpha}$ production dose dependently. Ginseng saponins did't inhibit the ADP($10{\mu}M$) induced platelet aggregation. but sodium arachidonate (0.5 mM) induced platelet aggregation. but sodium arachidonate (0.5 mM) induced platelet aggregation was signiticantly inhibited. These findings suggest that ginseng saponins seem to playa role in the regulation of the arachidonate metabolism. probably by affecting the divergent biosynthetic pathway of prostaglandins from endoperoxide.

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