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      • 전립선 기질세포의 증식과 COX-2 발현에 대한 프로게스테론의 영향

        정수련,김성한,최이화,박지은,전은미,강영진,이광윤,최형철 영남대학교 의과대학 2006 Yeungnam University Journal of Medicine Vol.23 No.1

        전립선비대증은 노인 남성에서 흔히 유발되는 질환이며, 노화가 진행될 수록 빈도가 높아지는 특징을 가진다. 이 질환의 원인은 전립선기질세표의 과도한 증식으로 유발된다고 알려져 있지만 그 자세한 기전에 대해서는 잘 알려져 있지 않다. 전립선비대증에서 progesterone 수용체 양성 세포가 다른 전립선 종양에 비해서 많고, progesterone은 testosterone에서 DHT로 전환되는 것을 감소시키는 역할을 가진다고 알려졋다. 또한 남성 전립선 평활근의 과증식에 의한 질환이므로 평활근 세포의 증식과 관련성이 있다고 보고된 COX-2의 전립선비대증에 대한 영향에 대한 연구가 필요하다. 전립선 기질세포에 progesterone을 3일간 투여하여 배양한 경우 기질세포 증식은 차이가 없었다. Progesterone을 단독 또는 DHT와 같이 투여한 기질세포에서 남성호르몬 수용체 mRNA 발현은 비처리군과 비교하여 유의한 차이가 없었다. 또한 progesterone과 DHT 동시 투여에 의한 COX-2 mRNA 발현에도 차이가 없었다. 그러나 progesterone에 의한 남성 호르몬 수용체와 COX-2 단백 발현에서는 대조군과 비교하여 유의하게 감소시켰다. 이상의 결과는 progesterone은 남성호르몬 수용체에 대해 전사 후 반응 (post-transcriptional response)에 효과를 나타내어 남성호르몬 수용체 발현을 감소시키는 작용은 가지며, COX-2 발현 억제효과를 나타내므로 전립선비대증의 치료에 이용될 수 있을 것으로 사료된다. Background: Benign prostatic hyperplasia (BPH) is the most common benign tumor in older men; the etiology of this disease remains poorly understood. Testosterone and dihydrotestosterone (DHT) both act as androgen via a single androgen receptor. Testosterone is converted to DHT by 5α-reductase in prostatic stromal cells. Progesterone has been reported to inhibit DHT conversion; howevwe, its effect on prostatic stromal cells remains to be elucidated. Materials and Methods: In this experiment, we investigated the effect of progesterone on androgen receptor expression induced by DHT. We also tested the effect of progesterone on cyclooxygenase-2 (COX-2) expression, as well as prostate stromal cell proliferation using the cell count kit-8. Results: Progesterone did not cause an increase of prostate stromal cell proliferation. The mRNA expression of the androgen receptor and COX-2 were not changed by progesterone; the expressions of androgen receptor and COX-2 proteins were decreased by progesterone in prostate stromal cells. Conclusion: These results suggest that in prostate stromal cells, progesterone decreases androgen receptor protein expression, which results in decrement of COX-2 protein expression. This effect might be mediated by post-transcriptional regulation.

      • SCOPUSKCI등재

        Fluorescence Quenching of Norfloxacin by Divalent Transition Metal Cations

        Park, Hyoung-Ryun,Seo, Jung-Ja,Shin, Sung-Chul,Lee, Hyeong-Su,Bark, Ki-Min Korean Chemical Society 2007 Bulletin of the Korean Chemical Society Vol.28 No.9

        Fluorescence quenching of norfloxacin (NOR) by Cu2+, Ni2+, Co2+ and Mn2+ was studied in water. The change in the fluorescence intensity and lifetime was measured as a function of quencher concentration at various temperatures. According to the Stern-Volmer plots, the NOR was quenched both by collisions and complex formation with the same quencher. However, the static quenching had a more important effect on the emission. Large static and dynamic quenching constants support significant ion-dipole and orbital-orbital interactions between NOR and cations. The both quenching constants by Cu2+ were the largest among quenchers. Also, quenching mechanism of Cu2+ was somewhat different. The change in the absorption spectra due to the quencher provided information on static quenching. The fluorescence of NOR was relatively insensitive to both the dynamic and static quenching compared with other quinolone antibiotics. This property can be explained by the twisted intramolecular charge transfer.

      • SCOPUSKCI등재

        Quenching of Ofloxacin and Flumequine Fluorescence by Divalent Transition Metal Cations

        Park, Hyoung-Ryun,Oh, Chu-Ha,Lee, Hyeong-Chul,Choi, Jae-Gyu,Jung, Beung-In,Bark, Ki-Min Korean Chemical Society 2006 Bulletin of the Korean Chemical Society Vol.27 No.12

        This study examined the quenching of ofloxacin (OFL) and flumequine (FLU) fluorescence by $Cuj^{2+}$, $Ni^{2+}$, $Co^{2+}$ and $Mn^{2+}$ in an aqueous solution. The change in the fluorescence intensity and lifetime was measured at various temperatures as a function of the quencher concentration. According to the Stern-Volmer plots, the fluorescence emission was quenched by both collisions (dynamic quenching) and complex formation (static quenching) with the same quencher but the effect of static quenching was larger than that of dynamic quenching. Large static and dynamic quenching constants for both OFL and FLU support significant ion-dipole and orbital-orbital interactions between fluorophore and quencher. For both molecules, the static and dynamic quenching constants by $Cu^{2+}$ were the largest among all the metal quenchers examined in this study. In addition, both the static and dynamic quenching mechanisms by $Cu^{2+}$ were somewhat different from the quenching caused by other metals. Between $Ni^{2+}$ and FLU, a different form of chemical interaction was observed compared with the interaction by other metals. The change in the absorption spectra as a result of the addition of a quencher provided information on static quenching. With all these metals, the static quenching constant of FLU was larger than those of OFL. The fluorescence of OFL was quite insensitive to both the dynamic and static quenching compared with FLU. This property of OFL can be explained by the twisted intramolecular charge transfer in the excited state.

      • KCI등재

        Spectroscopic Properties of Flavonoids in Various Aqueous-Organic Solvent Mixtures

        Hyoung-Ryun Park,Yu Daun,박종근,박기민 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.1

        The characteristic fluorescence properties of quercetin (QCT) and apigenin (API) were studied in various CH3OH-H2O and CH3CN-H2O mixed solvents. The structure of QCT is completely planar. API is not planar at the ground state but becomes nearly planar at the excited state. If the molecules are excited to the S1 state in organic solvents, QCT exhibits no fluorescence due to excited state intramolecular proton transfer (ESIPT) between the -OH and the carbonyl oxygen, but API shows significant fluorescence because ESIPT occurs slowly. If the molecules are excited to the S2 state, both QCT and API exhibit strong S2 → So emission without any dual fluorescence. As the H2O composition of both solvents increases, the fluorescence intensity decreases rapidly due to the intermolecular hydrogen bonding interaction. The theoretical calculation further supports these results. The change in fluorescence properties as a function of the solvatochromic parameters was also studied.

      • KCI등재

        Quenching of Ofloxacin and Flumequine Fluorescence by Divalent Transition Metal Cations

        Hyoung-Ryun Park,Chu-Ha Oh,Hyeong-Chul Lee,Jae Gyu Choi,Beung-In Jung,Ki-Min Bark* 대한화학회 2006 Bulletin of the Korean Chemical Society Vol.27 No.12

        This study examined the quenching of ofloxacin (OFL) and flumequine (FLU) fluorescence by Cu2+, Ni2+, Co2+ and Mn2+ in an aqueous solution. The change in the fluorescence intensity and lifetime was measured at various temperatures as a function of the quencher concentration. According to the Stern-Volmer plots, the fluorescence emission was quenched by both collisions (dynamic quenching) and complex formation (static quenching) with the same quencher but the effect of static quenching was larger than that of dynamic quenching. Large static and dynamic quenching constants for both OFL and FLU support significant ion-dipole and orbital-orbital interactions between fluorophore and quencher. For both molecules, the static and dynamic quenching constants by Cu2+ were the largest among all the metal quenchers examined in this study. In addition, both the static and dynamic quenching mechanisms by Cu2+ were somewhat different from the quenching caused by other metals. Between Ni2+ and FLU, a different form of chemical interaction was observed compared with the interaction by other metals. The change in the absorption spectra as a result of the addition of a quencher provided information on static quenching. With all these metals, the static quenching constant of FLU was larger than those of OFL. The fluorescence of OFL was quite insensitive to both the dynamic and static quenching compared with FLU. This property of OFL can be explained by the twisted intramolecular charge transfer in the excited state.

      • SCOPUSKCI등재
      • SCOPUSKCI등재

        Spectroscopic Properties of Flavonoids in Various Aqueous-Organic Solvent Mixtures

        Park, Hyoung-Ryun,Daun, Yu,Park, Jong Keun,Bark, Ki-Min Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.1

        The characteristic fluorescence properties of quercetin (QCT) and apigenin (API) were studied in various $CH_3OH-H_2O$ and $CH_3CN-H_2O$ mixed solvents. The structure of QCT is completely planar. API is not planar at the ground state but becomes nearly planar at the excited state. If the molecules are excited to the $S_1$ state in organic solvents, QCT exhibits no fluorescence due to excited state intramolecular proton transfer (ESIPT) between the -OH and the carbonyl oxygen, but API shows significant fluorescence because ESIPT occurs slowly. If the molecules are excited to the $S_2$ state, both QCT and API exhibit strong $S_2{\rightarrow}S_o$ emission without any dual fluorescence. As the $H_2O$ composition of both solvents increases, the fluorescence intensity decreases rapidly due to the intermolecular hydrogen bonding interaction. The theoretical calculation further supports these results. The change in fluorescence properties as a function of the solvatochromic parameters was also studied.

      • SCOPUSKCI등재

        Photochemical Reaction of Nalidixic Acid in Methanol

        Park, Hyoung-Ryun,Park, Ok-Hyun,Lee, Hong-Yune,Seo Jung-Ja,Bark, Ki-Min Korean Chemical Society 2003 Bulletin of the Korean Chemical Society Vol.24 No.11

        The photochemical reactions of methanolic nalidixic acid (NAL) solution in the absence and in the presence of air have been investigated using 300 nm UV light. From the reactions, 1-ethyl-7-methyl-4-oxo-4-hydro-1,8-naphthyridine (EMDN),formic acid, and formaldehyde are produced. In the presence of air, hydrogen peroxide is also detected along with the products listed above. The presence of oxygen during the irradiation of methanolic NAL solution effects on the product yield. The initial quantum yields of the products and of the NAL decomposition are determined. Possible reaction pathways for the photochemical reaction are suggested on the basis of the products analysis.

      • PHOTOCHEMICAL REACTION OF CHLOROFORM

        Park, Hyoung-Ryun,Jeong, Young-Tae,Ko, Song-Kyong,Oh, Jong-Hoon,Ham, Heui-Suk Korean Society of Photoscience 1997 Journal of Photosciences Vol.4 No.1

        The photochemical reactions of the neat chloroform and the aqueous chloroform in the absence (saturated with argon) and presence of 02 (saturated with air or oxygen) have been investigated using 184.9 nm UV light. The irradiation of the deoxygenated neat chloroform causes the formation of hexachloroethane, pentachloroethane, and 1, 1, 2, 2-tetrachloroethane. The initial quantum yields of the products were determined to be 6.37 x 10$^{-4}$, 4.04 x 10$^{-4}$ and 1.76 x 10$^{-4}$, respectively. In the irradiation of aqueous chloroform, chloride ion was also formed along with the products listed above and 1, 1, 2, 2-tetrachloroethane was the predominant product among the chlorinated organic products, which contrasts to the case of the neat chloroform. The presence of oxygen during the irradiation of aqueous chloroform had an effect on the yield of the products. With increasing the concentration of oxygen, the formation of the products was decreased. Probable reaction mechanisms for the photochemical reaction were presented on the basis of products analysis.

      • SCOPUSKCI등재

        Spectroscopic Properties of Quercetin in AOT Reverse Micelles

        Park, Hyoung-Ryun,Im, Seo-Eun,Seo, Jung-Ja,Bark, Ki-Min Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.3

        The spectroscopic properties of quercetin (QCT) were studied in the AOT reverse micelle by fluorescence spectroscopy. Because the molecular structure of QCT is completely planar, excited state intramolecular proton transfer (ESIPT) occurs between the -OH at C(5) and carbonyl oxygen via intramolecular hydrogen bonding. This ESIPT happens at the $S_1$ state but not at the $S_2$ state. Because QCT is a good donor-acceptor-conjugated molecule at the excited state, this molecule can emit strong fluorescence but shows no $S_1{\rightarrow}S_o$ emission due to this ESIPT. Since the $S_2{\rightarrow}S_1$ internal conversion was very slow due to the small Franck-Condon factors, $S_2{\rightarrow}S_o$ fluorescence emission was observed. All of the experimental results indicated that the QCT resided at the bound water interface and that the position of solute did not change significantly in the micelle at various water concentrations.

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