• 한국산업보건학회지
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• 제19권1호
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• pp.73-79
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• 2009

This study was undertaken to investigate the effects of single and combined exposure of toluene (T) and xylene (X) on the cytochrome-450(CYP)-mediated metabolizing capacity, induction of CYP isozymes and the excretion of their metabolites in urine. Animal were adults male Sprague-Dawley (SD) rats and divided into 4 groups such as control, T (treated with 63.7 mg/body kg), X (treated with 65.9 mg/body kg) and TX(T=X). Organic solvents was administrated by intraperitoneal injection for 3 days. The contents of protein and CYP in liver microsomes of control group were $16.48{\pm}0.56 mg/m{\ell}$ and $0.744{\pm}0.025$ nmol/mg protein, respectively, and they contents were significantly lower than in derived from treated groups (p<0.01). The activities of PROD and ${\rho}NPH$ were significantly higher in single treated groups than in control and combined group (TX). When Western immunoblotting were carried out with two monoclonal antibodies (MAb 1-98-1 and MAb 2-66-3) which were specific against CYP2B1/2 and CYP2E1, respectively, a strong signal corresponding to CYP2B1/2 was observed in microsomes obtained from rats treated with X and TX. The color density against CYP2E1 was slightly increased in T and TX groups compared with C and X groups. The amounts of urinary hippuric acid in T single treated group was $3.29{\pm}1.97$ g/g creatinine and TX combined group was $2.91{\pm}1.76$ g/g creatinine, but was not significant. However, amount of urinary methy hippuric acid in X single treated group ($1.62{\pm}0.72$ g/g creatinine) was significantly higher than TX combined group ($0.93{\pm} 0.63$ g/g creatinine)(p<0.01). These results suggested that CYP2E1 isozyme might be responsible for the metabolism of T, and CYP2B1/2 isozyme is for X. And also, difference of metabolites level between single and combined group may be speculated that the intermediates of T and X interacted each other in the process of their metabolite formation reaction.

• 대한약리학회지
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• 제26권2호
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• pp.145-152
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• 1990

최근 본 교실에서는 two-bath system을 이용하여 혈관 내피세포에서 superoxide에 의존한 혈관 이완성 물질을 동정하여 발표하였다. 본 실험에서는 상기 system을 이용하여 돼지의 관상동맥 내피세포에서 유리되는 superoxide에 의존한 이완성 물질이 고양이의 흥부 대동맥 내피 및 소의 대동맥 배양내피세포에서 얻어진 이완성 물질에 의한 이완과 매우 유사함을 관찰하여 다음과 같은 결과를 얻었다. 1. 고양이 흥부 대동맥, 돼지 관상동맥의 내피세포 및 소 대동맥 배양 내피세포 등에서 유리되는 superoxide에 의존한 이완 물질은 모두 유사한 이완 작용을 나타내었다. 2. 돼지 관상 동맥 내피세포에서 유리되는 superoxide 의존성 이완 물질이 고양이의 흥부 대동맥 내피세포나 소의 대동맥 배양 내피세포에서 유리되는 이완 물질과는 다소 다른 점도 있었다. 즉, 돼지 관상동맥 내피세포에서 유리되는 이완 물질의 작용은 catalase나 superoxide dismutase(SOD)에 의하여 억제되었으나, 후자의 두 동맥 내피세포에서 유리되는 이완 물질은 SOD에 의해서만 억제되었다. 3. 이러한 이완성 물질들의 생성은 여러 lipoxygenase억제제인 gossypol, nordihydroguaiaretic acid, AA 861 및 eicosatetraynoic acid 등의 전처치에 의하여 봉쇄되었다. 4. Cyclooxygenase 억제제인 indomethacin이 나 cytochrome P-450 monooxygenase 억제제인 proadifen과 cimetidine에 의하여는 봉쇄되지 아니하였다. 이상의 결과로부터 이러한 이완성 물질들은 비록 각기 다른 종의 동물 모델에서 얻었다고 하더라도 장기에 따라 다소 반응의 차이는 있으나 동질성 이완 물질이며, 나아가 이러한 이완성 물질은 여러 조직의 허혈-재관류 손상에 있어서 병리생리학적으로 관련될 것으로 사료된다.

• The Korean Journal of Physiology and Pharmacology
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• 제3권1호
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• pp.83-91
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• 1999

Angiotensin II (ANG II) has a biphasic effect on $Na^+$ transport in proximal tubule: low doses of ANG II increase the $Na^+$ transport, whereas high doses of ANG II inhibit it. However, the mechanisms of high dose ANG II-induced inhibition on $Na^+$ uptake are poorly understood. Thus the aim of the present study was to investigate signal transduction pathways involved in the ANG II-induced inhibition of $Na^+$ uptake in the primary cultured rabbit renal proximal tubule cells (PTCs) in hormonally defined serum-free medium. ANG II $(10^{-9}\;M)-induced$ inhibition of $Na^+$ uptake was blocked by losartan $(10^{-8}\;M,\;AT_1\;antagonist),$ but not by PD123319 $(10^{-8}\;M,\;AT_2\;antagonist)$ (P<0.05). ANG II-induced inhibition of $Na^+$ uptake was also completely abolished by neomycin $(10^{-4}\;M,$ PLC inhibitor), W-7 $(10^{-4}\;M,$ calmodulin antagonist), and $AACOCF_3\;(10^{-6}\;M,\;PLA_2\;inhibitor)$ (P<0.05). ANG II significantly increased $[^3H]arachidonic$ acid (AA) release compared to control. The ANG II-induced $[^3H]AA$ release was blocked by losartan, $AACOCF_3,$ neomycin, and W-7, but not by PD123319. ANG II-induced $[^3H]AA$ release in the presence of extracellular $Ca^{2+}$ was greater than in $Ca^{2+}-free$ medium, and it was partially blocked by TMB-8 $(10^{-4}\;M,$ intracelluar $Ca^{2+}$ mobilization blocker). However, in the absence of extracellular $Ca^{2+},$ it was completely blocked by TMB-8. In addition, econazole $(10^{-6}\;M,$ cytochrome P-450 monooxygenase inhibitor) and indomethacin $(10^{-6}\;M,$ cyclooxygenase inhibitor) blocked ANG II-induced inhibition of $Na^+$ uptake, but NGDA $(10^{-6}\;M,$ lipoxygenase inhibitor) did not affect it. In conclusion, $PLA_2-mediated$ AA release is involved in ANG II-induced inhibition of $Na^+$ uptake and is modulated by $[Ca^{2+}]_i$ in the PTCs.

• 한국응용곤충학회지
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• 제35권3호
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• pp.254-259
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• 1996

Yumenoshima III 집파리 계통을 ethyl fenitrothion으로 30세대 도태시킨 EF-30 계통에 있어서의 parathion 저항성 메카니즘을 생화학적으로 조사하였다. 아세틸콜린에스테라제 저해활성은 저항성계통과 감수성 SRS 계통간에 커다란 차이를 보여 이 효소의 감수성 저하가 저항성의 주료 메카니즘으로 작용하고 있음을 알 수 있었다. 양 계통에 있어서의 parathion과 paraoxon의 in vitro 분해활성은 미크로좀 및 수용성 분획과 관련이 있으며, 각각 NADPH와 glutathione을 필요로 하였다. 저항성계통은 감수성계통에 비하여 GSH S-transferase 활성이 높아 이 효소가 저항성 메카니즘에 중요한 역할을 하고 있는 것으로 추정되었다. 저항성계통은 parathion에 대하여 101,487배, ethyl parathion에 대하여 25,914배의 저항성비를 나타내어 parathion이 GSH S-transferase의 기질로 작용하고 있음을 알 수 있었다. 이상의 결과로부터 EF-30 계통에 있어서의 저항성 메카니즘에는 수종의 요인이 관여하여 parathion에 대하여 높은 저항성을 나타냄을 알 수 있었으나, 이들 요인이외에 타 요인의 관여를 배제할 수 없었다.

• 생명과학회지
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• 제20권1호
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• pp.133-141
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• 2010

LED의 간 보호 기능을 연구하기 위하여 $CCl_4$ 및 ethanol로 SD rat에 간독성을 유발한 다음, LED를 처리하였다. LED의 간 기능 보호효과는 간장치료제인 Silymarin과 비교하였다. $CCl_4$로 간 독성을 유발한 경우, LED는간의 항산화효소인 SOD, catalase, GSH peroxidase 효소활성의 항진을 유도하였고, 산화물인 TBARS의 함량을 감소시켰다. 또한 간 손상의 지표인 혈장의 GOT, GPT 및 LDH의 활성을 감소시켰다. Ethanol로 간 독성을 유발한 경우 LED는 간의 SOD, catalase, GSH preoxidase 효소활성 및 GSH 함량을 항진시켰고, 총 cholesterol, triglyceride 및 TBARS의 함량을 감소시켰다. 또한 ethanol 대사에 관여하는 ADH 효소 활성을 증진시켰고, ROS 생성에 관여하는 CYP2E1 효소의 발현을 감소시킴으로써, 혈장의 GOT, GPT 및 LDH 효소활성이 감소되었다. 또한 LED는 DPPH 및 mouse liver mitochondrial system에서 항산화효과를 보였다. 이러한 결과로 미루어 볼 때 LED는 in vitro와 in vivo에서 항산화효과에 의한 간 기능 보호효과를 갖는 것으로 추정된다.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2014년도 춘계학술대회 및 임시총회
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• pp.27-28
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• 2014

Beauveria bassiana (Cordycipitaceae, Hypocreales, Ascomycota) is an anamorphic fungus having a potential to be used as a biological control agent because it parasitizes a wide range of arthropod hosts including termites, aphids, beetles and many other insects. A number of bioactive secondary metabolites (SMs) have been isolated from B. bassiana and functionally verified. Among them, beauvericin and bassianolide are cyclic depsipeptides with antibiotic and insecticidal effects belonging to the enniatin family. Non-ribosomal peptide synthetases (NRPSs) play a crucial role in the synthesis of these secondary metabolites. NRPSs are modularly organized multienzyme complexes in which each module is responsible for the elongation of proteinogenic and non-protein amino acids, as well as carboxyl and hydroxyacids. A minimum of three domains are necessary for one NRPS elongation module: an adenylation (A) domain for substrate recognition and activation; a tholation (T) domain that tethers the growing peptide chain and the incoming aminoacyl unit; and a condensation (C) domain to catalyze peptide bond formation. Some of the optional domains include epimerization (E), heterocyclization (Cy) and oxidation (Ox) domains, which may modify the enzyme-bound precursors or intermediates. In the present study, we analyzed genomes of B. bassiana and its allied species in Hypocreales to verify the distribution of NRPS-encoding genes involving biosynthesis of beauvericin and bassianolide, and to unveil the evolutionary processes of the gene clusters. Initially, we retrieved completely or partially assembled genomic sequences of fungal species belonging to Hypocreales from public databases. SM biosynthesizing genes were predicted from the selected genomes using antiSMASH program. Adenylation (A) domains were extracted from the predicted NRPS, NRPS-like and NRPS-PKS hybrid genes, and used them to construct a phylogenetic tree. Based on the preliminary results of SM biosynthetic gene prediction in B. bassiana, we analyzed the conserved gene orders of beauvericin and bassianolide biosynthetic gene clusters among the hypocrealean fungi. Reciprocal best blast hit (RBH) approach was performed to identify the regions orthologous to the biosynthetic gene cluster in the selected fungal genomes. A clear recombination pattern was recognized in the inferred A-domain tree in which A-domains in the 1st and 2nd modules of beauvericin and bassianolide synthetases were grouped in CYCLO and EAS clades, respectively, suggesting that two modules of each synthetase have evolved independently. In addition, inferred topologies were congruent with the species phylogeny of Cordycipitaceae, indicating that the gene fusion event have occurred before the species divergence. Beauvericin and bassianolide synthetases turned out to possess identical domain organization as C-A-T-C-A-NM-T-T-C. We also predicted precursors of beauvericin and bassianolide synthetases based on the extracted signature residues in A-domain core motifs. The result showed that the A-domains in the 1st module of both synthetases select D-2-hydroxyisovalerate (D-Hiv), while A-domains in the 2nd modules specifically activate L-phenylalanine (Phe) in beauvericin synthetase and leucine (Leu) in bassianolide synthetase. antiSMASH ver. 2.0 predicted 15 genes in the beauvericin biosynthetic gene cluster of the B. bassiana genome dispersed across a total length of approximately 50kb. The beauvericin biosynthetic gene cluster contains beauvericin synthetase as well as kivr gene encoding NADPH-dependent ketoisovalerate reductase which is necessary to convert 2-ketoisovalarate to D-Hiv and a gene encoding a putative Gal4-like transcriptional regulator. Our syntenic comparison showed that species in Cordycipitaceae have almost conserved beauvericin biosynthetic gene cluster although the gene order and direction were sometimes variable. It is intriguing that there is no region orthologous to beauvericin synthetase gene in Cordyceps militaris genome. It is likely that beauvericin synthetase was present in common ancestor of Cordycipitaceae but selective gene loss has occurred in several species including C. militaris. Putative bassianolide biosynthetic gene cluster consisted of 16 genes including bassianolide synthetase, cytochrome P450 monooxygenase, and putative Gal4-like transcriptional regulator genes. Our synteny analysis found that only B. bassiana possessed a bassianolide synthetase gene among the studied fungi. This result is consistent with the groupings in A-domain tree in which bassianolide synthetase gene found in B. bassiana was not grouped with NRPS genes predicted in other species. We hypothesized that bassianolide biosynthesizing cluster genes in B. bassiana are possibly acquired by horizontal gene transfer (HGT) from distantly related fungi. The present study showed that B. bassiana is the only species capable of producing both beauvericin and bassianolide. This property led to B. bassiana infect multiple hosts and to be a potential biological control agent against agricultural pests.