• Archives of Pharmacal Research
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• 제21권4호
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• pp.436-439
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• 1998

In order to find out anti-platelet activating factor (PAF) from natural resources, Korean medicinal plants used for the treatments of peripheral circulation disorders were tested for their possible protective effects on PAF-induced anaphylactic shock. From the above screening, the methanol extract of Gentiana scabra showed a potent antagonistic activity against PAF. Water suspension of the extract was partitioned with $CH_2$$CI_2$ and EtOAc, successively. The EtOAc fraction which showed the highest activity was chromatographed on silica gel to yield 6 fractions. From the fraction which showed higher PAF-antagonistic activity than the other fractions, compound 1 was isolated by recrystallization. On the basis of spectral data, compound 1 was identified as 2-hydroxy-3-methoxybenzoic acid glucose ester. The compound prevented the mice from the PAF-induced death at a dose of 300 $\mu\textrm{g}$/mouse.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1999년도 한국생물과학협회 학술발표대회
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• pp.301-301
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• 1999

No Abstract, See Full Text

• The Korean Journal of Physiology and Pharmacology
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• 제4권2호
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• pp.99-104
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• 2000

We investigated the action of NOS inhibitors on NOS in rats. Both of nitric oxide synthase inhibitors, $N^G$-monomethyl-L-arginine $(L-NMMA,\;3\;{\mu}M)$ or $N^G$-nitro-L-arginine methylester $(L-NAME,\;30\;{\mu}M),$ augmented phenylephrine $(PE,\;10^{-7}\;M)-induced$ contraction which was inhibited by acetylcholine (ACh) in rat thoracic aorta. This augmentation by L-NAME or L-NMMA was attenuated with the treatment of NO precursor, arginine. ACh, however, decreased the augmentation induced by L-NMMA, but not by L-NAME. Superoxide dismutase (SOD, 50 u/ml) potentiated an inhibitory effect of ACh on the PE $(10^{-7}\;M)-induced$ contraction. It has been known that platelet activating factor itself induces iNOS. Platelet activating factor $(PAF,\;10^{-7}\;M)$ inhibited PE $(10^{-7}\;M)-induced$ contraction. Pretreatment with L-NMMA (30 mM) or L-NAME (30 mM) significantly blocked the inhibitory action of PAF on PE-induced contraction. L-NMMA (100 mM) or L-NAME (100 mM) reduced nerve conduction velocity (NCV) relevant to nNOS in rat sciatic nerve. ACh attenuated the reduction of NCV by L-NMMA-, but not by L-NAME-induced reduction of NCV. These results suggest that L-NMMA and/or L-NAME have different action on three types of NOS in rats.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1996년도 한국생물과학협회 국제학술대회
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• pp.261.1-261
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• 1996

No Abstract, See Full Text

• Journal of Yeungnam Medical Science
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• 제25권1호
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• pp.41-49
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• 2008

한탄바이러스가 혈소판활성인자 활성에 영향을 미치는지 알아보기 위하여 간접적으로 혈소판활성인자 수용체의 발현과 분해효소의 활성을 측정하였다. 혈관내피세포에서 혈소판활성인자 수용체의 유전자를 역전사 중합효소연쇄반응으로, 단백질은 western blot으로 측정하였다. 또한 세포표면에 발현된 혈소판활성인자 수용체의 양은 FACS로 분석하였다. 한탄바이러스에 감염된 혈관내피세포에서 혈소판활성인자 수용체의 유전자, 단백질, 세포 표면의 발현 모두 바이러스에 감염되지 않은 대조 세포보다 감염 후 2, 3일째 증가 하였다. 혈액 내 혈소판활성인자 분해효소의 활성을 비교한 결과 신증후출혈열 환자에서 정상인에 비하여 2.5배 낮았다. 그리고 신증후출혈열 환자가 회복됨에 따라 혈소판활성인자의 활성이 다시 정상 수준으로 회복되는 것으로 나타났다. 따라서 한탄바이러스에 의해 증가된 혈소판활성인자 수용체의 발현이 혈소판활성인자와 혈관내피세포와 반응성을 증가시키고, 신증후출혈열 환자 혈액에서 감소된 혈소판활성인자 분해효소가 혈소판활성인자의 분해를 지연 시켜 작용시간을 증가 시킴으로써 과다한 혈소판활성인자의 생물학적 작용이 신증후출혈열의 병리현상을 초래할 것으로 사료된다.

• Toxicological Research
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• 제14권3호
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• pp.333-339
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• 1998

Sambutoxin, a newly purified mycotoxin in Koea, caused hemorrhage in the stomach and intestine of rats. To elucidate the mechanism of hemorrhage, effects of sambutoxin on rabbit platelet aggregation were investigated. First of all, the effects of sambutoxin on the platelet aggregation response and ATP release from platelet by various appregating factors were investigated. And then the role of $Ca^{2+}$ on the platelet aggregation was investigated by flow cytometer. Finally, morphological effect of sambutoxin on platelet ultrastructure was examined by transmission electron microscope. Sambutoxin inhibited aggregation induced by ADP, collagen, thrombin, and arachidonic acid and decreased platelet activating factor-induced disaggregation time in a dose dependent manner. Sambutoxin also decreased thrombin and arachidonic acid-induced ATP release, but increased all factors induced $Ca^{2+}$ release. Sambutoxin showed severe ultrastructural changes of platelet such as appearance of disorganization debri of cellular organelle in intercellular space. Our results indicate that sambutoxin inhibitis rabbit platelet aggregation, and it may be party due to the decrease of ATP release. However, it is not clear whether the antiaggregating effect of sambutoxin is related to $Ca^{2+}$ increase.

• Biomolecules & Therapeutics
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• 제14권3호
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• pp.160-165
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• 2006

Since platelet-activating factor (PAF) is involved in inflammation, allergic response and anaphylactic shock, PAF receptor antagonists may have potential for controlling these disease conditions. The extract of the leaves of Ginkgo biloba having a higher content of terpenoids (12%) with flavonoids (24%) (YY1224) was prepared in order to obtain the increasing PAF antagonistic activity. As expected, YY1224 showed a higher PAF antagonistic binding affinity ($IC_{50}\;=\;0.09\;{\mu}g/ml$) using $[^3H]PAF$ and rabbit platelets as ligand and receptor source, compared with an $IC_{50}$ of $>\;100\;{\mu}g/ml$ by Egb 761, a standardized extract. YY1224 also showed a higher inhibitory activity against PAF-induced platelet aggregation and NO production from lipopolysaccharide-treated RAW 264.7 cells. In addition, it protected PAF-induced death in mice by oral administration at 15 mg/kg. All these results suggest that YY1224 may show favorable effects on PAF-related disorders.

• 대한약학회:학술대회논문집
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• 대한약학회 2001년도 Proceedings of International Convention of the Pharmaceutical Society of Korea
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• pp.218.2-219
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• 2001

• 한국동물학회:학술대회논문집
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• 한국동물학회 1999년도 한국생물과학협회 학술발표대회
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• pp.300.2-300
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• 1999

No Abstract, See Full Text

• 한국동물학회:학술대회논문집
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• 한국동물학회 1999년도 한국생물과학협회 학술발표대회
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• pp.300.1-300
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• 1999

No Abstract, See Full Text