흰쥐 간 마이크로좀의 Cytochrome P - 450 과 Testosterone 및 16α

손형옥,임흥빈,이영구,이동욱,박희윤 ( Hyung Ok Sohn,Heung Bin Lim,Young Gu Lee,Dong Wook Lee,Hee Yun Park ) 생화학분자생물학회 1992 BMB Reports Vol.25 No.4

The binding affinity of the differentially induced cytochrome P-450 (P-450) in rat liver microsomes with testosterone and 16α-hydroxytestosterone (16α-OH-T) was compared. Interaction of testosterone with all three microsomel P-450 of normal, MC- or PB-treated rats, gave type I spectral changes and their spectral binding constants (Ks) to P-450s were 35, 33, and 25 μM at 25℃, respectively. PB-inducible P-450s among three of these showed the highest affinity to testosterone, and the ratio of low to high spin conversion of P-450 by this compound showed also a similar tendency as the results of binding affinity. 16α-OH-T, one of testosterone metabolites, binding to all three P-450 exhibited a reversed type I spectral changes and their Ks values to normal, MC- and PB-inducible P-450 were 41, 28, and 23 μM, respectively, but binding of it with PB-inducible P-450 showed another Soret band near 460 nm. These results indicate that 16α-OH-T also binds to P-450s with a high affinity like testosterone, and it may be further metabolized to more polar compounds by P-450.

담배적용 생체내(in vivo) 평가;아만성 흡입독성 시험을 중심으로

손형옥,Sohn, Hyung-Ok 한국연초학회 2008 한국연초학회지 Vol.30 No.1

생물학적으로 활성이 있는 물질들의 생체 내 대사를 이해하고 인체 독성 및 질환의 발현을 예측할 수 있는 가장 좋은 시험방법은 생체 내 독성 평가법이다. 담배연기의 생체 내 독성 평가법에는 14일 흡입독성시험, 90일 흡입독성 시험 및 피부도말 종양발생 시험 등이 있다. 90일 흡입독성 시험은 담배의 일반적인 독성 정보를 제공한다. 생체 내 독성평가는 담배 첨가물, 재료품 또는 제품 설계를 변경할 경우 담배연기 독성이 증가 또는 감소되었는 지를 평가할 수 있으며 이 결과는 제품보증에 활용될 수 있다. 캐나다의 독성평가자료 제출 및 EU 등의 담배첨가물에 대한 규제는 향 후 이런 생체 내 시험에 대한 지속적이고도 구체적인 요구를 할 것으로 사료된다.

단백질 분해효소억제제를 이용한 담배의 품질평가

손형옥,임흥빈,이영구,이동욱,김용태 한국연초학회 1991 한국연초학회지 Vol.13 No.2

Current studies indicated that emphysema in smokers might be due, in part, to the local suppression of G, -protease inhibitor(u, -Pl) in lung by reactive oxygen species in cigarette smoke or smoke-activated lung neutrophiles. In the present works, we examined the possibility that a measure which inactivated $\alpha$l-Pl by cigarette smoke could be an alternative method to evaluate the cigarette quality, In order to determine the inactivation of $\alpha$1, -Pl, trypsin inhibitory capacity(TIC) was assayed. A rapid loss of $\alpha$1, -Pl activity occurred when $\alpha$1-Pl solutions was exposed the gas phase or total particulate matter(TPM) obtained from various brands. The inactivation of $\alpha$1-Pl by gas phase was dependent upon the number of puffs and the age of the smoke. However, that by TPM was rather decreased since 2 puffs and also showed no more change over 24hrs after exposing. Inactivation of $\alpha$1-Pl determined by our suggested method(5 puffs, 24hours of aging after exposing) using various commercial cigarettes exhibited that high tar brands has inactivated it more strongly than low tar cigarettes. But the ability of some brands to inactivate $\alpha$1-Pl does not correlate with the content of tar or nicotine. These results so여esc that the degree of $\alpha$1-Pl inactivation by cigarette smoke may be a useful index for the evaluation of cigarette quality and that it should be also contribute to the manufacture of less hazardous cigarettes.

담배 흡입독성 평가를 위한 설치류 담배연기노출시스템의 유효화

손형옥,이형석,신한재,박철훈,유지혜,장미,현학철,Sohn, Hyung-Ok,Lee, Hyeong-Seok,Shin, Han-Jae,Park, Chul-Hoon,Yoo, Ji-Hye,Jang, Mi,Hyun, Hak-Chul 한국연초학회 2014 한국연초학회지 Vol.36 No.1

As part of a balanced testing battery, subchronic inhalation studies on rats are performed to ensure that proposed cigarette modifications do not increase the toxicity of smoke and to demonstrate any instances where a modification may actually contribute to harm reduction. For subchronic inhalation studies with aerosols, the OECD suggests an exposure regimen of 6 hours/day (OECD Guideline 413, 1981), but alternative regimens have also been published: 1 hour/day and $2{\times}1$ hour/day. The aim of this study was to validate a rodent nose-only exposure system for the assessment of inhalation toxicity of cigarette smoke. In this study, cigarette smoke exposure system is consisted of cigarette smoke generator, smoke concentration adjusting system, and 20-port nose-only exposure system. Male SD rats were exposed for 35 days ($2{\times}1$ hour/day) to 3R4F Reference cigarette smoke and analysed major monitoring items of OECD Gudeline 413. WTPM, was measured in the test atmosphere, respiratory function (Buxco Biosystems) during exposure, postexposure urinary exposure biomarkers and alveolar neutrophiles in BAL fluid (Day 35) were evaluated. Validation demonstrated steady WTPM ($257{\pm}20ug/L$, $502{\pm}27ug/L$) and spatial uniformity (<10%). Nose port temperature ($22{\sim}26^{\circ}C$ and RH (45~75%) were acceptable over 35 days. Reductions in respiratory rate and minute volume and increase in the neutrophiles in BALF and the urinary exposure biomarkers were observed cigarette smoke dose dependently. This validation and 35-day inhalation study has shown that the rodent nose-only exposure system may be useful in the inhalation toxicity assessment of cigarette smoke.

담배연기응축물의 소핵생성 측정시 두가지 방법간의 민감성 비교

손형옥,이영구,한정호,허재연,이동욱,현학철,신한재,Sohn Hyung-Ok,Lee Young-Gu,Han Jung-Ho,Hur Jae-Yeon,Lee Dong-Wook,Hyun Hak-Chul,Shin Han-Jae 한국연초학회 2004 한국연초학회지 Vol.26 No.2

Among short-term in vitro genotoxicity assays, micronucleus assays are rapid, inexpensive, and less labor-intensive system. We have undertaken a comparative study of sensitivity of cigarette smoke condensate(CSC) by general micronucleus(MN) assay and cytokinesis-block micronucleus(CBMN) assay. In this study, V79 Chinese hamster cells were employed to evaluate and compare the genotoxicity of CSC of Kentucky Reference Cigarette 2R4F by 2 kinds of in vitro MN assay methods. To determine the optimum concentration of cytochalasin B(CYB) to obtain the maximal number of binucleated cells for CBMN assay, triplicate cultures of growing cells were treated with CYB for 15 h. CYB treatments caused a concentration-dependent increase in cytotoxicity($1\~4{\mu}g/mL$) and proportion($0.25\~1\;{\mu}g/mL$) of binucleated cells. These data suggested that 1 ug/mL of CYB is as an optimum dose for CBMN assay in binucleated V79 cells. Short treatment(4 h) of CSC induced a micronucleated cells with a concentration-dependent response in the presence or absence of CYB, but CSC-induced MNs were weakened when S9 was present. Long treatments(19 h) of CSC also induced a significant increase MN formation with a concentration-dependent response. At a concentration of 75 ${mu}g/mL$, the MN cell frequencies of general MN assay and CBMN assay were $6.5\%\;and\;11.7\%$, respectively. Linear regression analysis revealed a good correlation in CBMN assay between a concentration of CSC and MN cell frequency. All these data indicated that CBMN assay is more sensitive to the induction CSC-induced MN than general MN assay.

니코틴의 약리ㆍ생리 작용

손형옥,현학철,이영구,이윤환,이동욱 한국연초학회 2002 한국연초학회지 Vol.24 No.2

세포주에 따른 담배연기응축물의 소핵생성 비교

신한재,손형옥,이영구,이동욱,현학철 한국연초학회 2003 한국연초학회지 Vol.25 No.2

Although tobacco smoke has been known to have genotoxicity as well as cytotoxicity, the sensitivity of the cell lines used against cigarette smoke is poorly understood. The objective of this study was to evaluate and compare the genotoxicity of several cell lines, which are routinely used in the in vitro assays, with cigarette smoke condensate(CSC) of Kentucky Reference Cigarette 1R4F. In the micronucleus(MN) induction assays, murine(CHO-K1, V79, BALB/c 3T3) cell lines and human(MCF-7, A549) ones were used. As a result, the CSC exhibited cytotoxicity with a concentration-dependent response in all cell lines. EC$_{50}$ of CSC in CHO-K1, V79, BALB/c 3T3, MCF-7 and A549 were 140, 125, 100, 116 and 109 $\mu\textrm{g}$/mL, respectively. On the other hand, the spontaneous micronucleated cell(MNC) frequency was stable and reproducible in every cell lines tested in this study. The dose-response of various cell lines to the induction of MN by CSC was estimated using linear regression analysis. CSC(0~100 $\mu\textrm{g}$/mL) caused a dose-dependent MN induction in CHO-K1, V79, BALB/c 3T3 and MCF-7 cell lines. Putting together all the data obtained and linear regression analysis of the data, we concluded that V79 cells are more susceptible to the accurate assessment of CSC-induced MN than the others.s.

Metabolism of 16a - Hydroxytestosterone by Cytochrome P -450 in Rats Liver

임홍빈,손형옥,이영구,이동욱 생화학분자생물학회 1992 생화학분자생물학회 춘계학술발표논문집 Vol.- No.-

인삼의 항산화 작용 ( Antioxidant Action of Ginseng : An hypothesis )

이동욱,손형옥,임흥빈,이영구,A. G. Aprikian,G. V. Aprikian 고려인삼학회 1995 Journal of Ginseng Research Vol.19 No.1

인간 유래 폐 세포주별 담배연기 분획의 염증 반응 민감도 비교

유지혜,손형옥,박철훈,이형석,장미,현학철,신한재,Yoo, Ji-Hye,Sohn, Hyung-Ok,Park, Chul-Hoon,Lee, Hyeong-Seok,Jang, Mi,Hyun, Hak-Chul,Shin, Han-Jae 한국연초학회 2010 한국연초학회지 Vol.32 No.1

The aim of this study is to compare the sensitivity of both two NCI-H292 and A549 cell types to acute inflammatory responses induced by cigarette smoke. For this, we treated two kinds of smoke fractions derived from 2R4F reference cigarettes: total particulate matter(TPM) collected onto a Cambridge filter pad and gas/vapor phase(GVP) prepared by bubbling through in buffer solution. When we measured cellular cytotoxicity by neutral red uptake assay after treatment for 24 hours, TPM and GVP induced cytotoxic effect in a dose-dependent manner in the range of 10-$100{\mu}g$/mL and 60-$300 {\mu}g$/mL., respectively, in both cell types without any cellular difference. Additionally, when we examined acute inflammatory responses by analyzing cytokines secreted into culture media including tumor necrosis factor-$\alpha$ (TNF-$\alpha$), interleukin-8(IL-8), and transforming growth factor-$\alpha$(TGF-$\alpha$) as well as matrix metalloproteinase-1(MMP-1), the treatment with smoke fractions increased those marker proteins in a dose-dependent manner in NCI-H292. Meanwhile, in A549 cells only MMP-1 was observed to be increased in a dose-dependent fashion. Collectively, our data indicate that NCI-H292 cell type is more sensitive to cigarette smoke-induced inflammatory response than A549 cells. This suggests that NCI-H292 could be useful as an in vitro evaluation tool to assess harmful effects of cigarette smoke.