• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.56-56
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• 1995

자연계에 널리 분포하고 있는 flavonoid 유도체들은 다양한 구조에 따라, 다양한 생물활성을 보인다. 최근에는 이들이 cyclooxygenase/lipoxygenase를 저해한다는 사실이 알려진 후에 이들 유도체들을 항염증제 또는 항알레르기 약물로 개발하려는 시도가 계속되고 있다. 이들 연구의 일환으로 본 연구자들은 여러 flavonoid유도체들에 대한 in vivo 항염증능 및 림프구증식억제능을 보고하였다 (Arch. Pharm. Res. 16, 18, 25 (1993), 17, 31, 236 (1994), Life Sci. 54, 313 (1994)). 또한 flavonoid 유도체들 중 apigenin-dimer인 수종의 biflavonoid들이 group II phospholipase $A_2$ 저해제인 것을 밝혔고 (BBRC 205, 843 (1994)), 이들 중 몇 종은 림프구증식능에 대하여 억제작용을 보인다는 것을 알았다 (Life Sci. in revision). 본 연구에서는 이들 biflavonoid 유도체들 중 amentoflavone과 ginkgetin을 중심으로 이들의 림프구증식억제능 및 in vivo에서의 항염증작용을 연구하였다. 그 결과, ginkgetin (1-10 $\mu$M)은 Con A와 LPS에 의해 유도되는 림프구중식을 비가역적으로 억제하였으며, 이들 유도체들은 마우스 귀부종에 대하여 복강내투여에서 강력한 항염증능을 보인다는 것을 알았다.

• Radiation Oncology Journal
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• v.15 no.2
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• pp.79-95
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• 1997

Purpose : Phospholipase C(PLC) isozymes play significant roles in signal transduction mechanism. $PLC-\gamma$ 1 is one of the key regulatory enzymes in signal transduction for cellular proliferation and differentiation. Ras oncoprotein, EGFR, and PKC are also known to be involved in cell growth. The exact mechanisms of these signal transduction following irradiation, however, were not clearly documented Thus, this study was Planned to determine the biological significance of PLC, ras oncoprotein, EGFR, and PKC in damage and regeneration of rat intestinal mucosa following irradiation. Material and Method : Sixty Sprague-Dawley rats were irradiated to entire body with a single dose of 8Gy. The rats were divided into S groups according to the sacrifice days after irradiation. The expression of PLC, ras oncoprotein, EGFR and PKC in each group were examined by the immunoblotting and immunohistochemistry. The histopathologic findings were observed using H&I stain, and the mitoses for the evidence of regeneration were counted using the light microscopy & PCNA kit. The Phosphoinositide(PI) hydrolyzing activity assay was also done for the indirect evaluation of $PLC-\gamma$ 1 activity. Results: In the immunohistochemistry , the expression of $PLC-{\beta}$ was negative for all grøups. The expression of $PLC-{\gamma}1$ was highest in the group III followed by group II in the proliferative zone of mucosa. The expression of $PKC-{\delta}1$ was strongly positive in group 1 followed by group II in the damaged surface epithelium. The above findings were also confirttled in the immunoblotting study. In the immunoblotting study, the expressions of $PLC-{\beta}$, $PLC-{\gamma}1$, and $PKC-{\delta}1$ were the same as the results of immunohis-tochemistry. The expression of ras oncoprctein was weakly positive in groups II, III and IV. The of EGFR was the highest in the group II, III, follwed by group IV and the expression of PKC was weakly positive in the group II and III. Conclusion: $PLC-{\gamma}1$ mediated signal transduction including ras oncoprotein, EGFR, and PKC play a significant role in mucosal regeneration after irradiation. $PLC-{\delta}1$ mediated signal transduction might have an important role in mucosal damage after irradiation. Further studies will be necessary to confirm the signal transduction mediating the $PKC-{\delta}1$.