• Animal cells and systems
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• 제8권2호
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• pp.97-103
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• 2004

The cytotoxic effect of iron was examined in peritoneal macrophage to determine contributing factors by iron injection to rat. Viability was reduced by 24% by the iron-overload and by 30% by short-term iron addition. Total iron was increased by 45% in the iron-overloaded with remarkable elevation (9 to 14 fold) in the presence of $FeSO_4$. Free calcium was also increased by 19% in control and 44% in iron-overloaded group due to additional $FeSO_4$ NO and MDA were increased by 40% and 136%, respectively, with significant reduction (37%) of NAD(P)H. RCR and cytochrome c oxidase activity were lowered approximately by 10% with reduction of mitochondrial membrane potential. Addition of iron was frequently associated with altered distribution of mitochondria of high membrane potential in the iron-overloaded macrophage. These results suggest altered mitochondria with high NO and low NAD(P)H due to iron.

• 대한수의학회지
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• 제48권3호
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• pp.337-345
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• 2008

There are accumulating evidences that high levels of dietary iron may play a role in colon carcinogenesis. Elevated iron status has been associated with oxidative stress. Phytic acid (PA) functions as an antioxidant by chelating divalent cations and prevents formation of reactive oxygen species responsible for cell injury and carcinogenesis. The protective effect of PA was investigated on formation of aberrant crypt foci (ACF) induced by azoxymethane (AOM) in iron-overloaded male F344 rats. After acclimation with AIN-93G purified diet (35 ppm Fe, normal control diet) for one week, animals were fed iron-overloaded diet (350 ppm Fe) and PA (0.5% or 2% PA in water) for 8 weeks. Animals received two (1st and 2nd week) injections of AOM (15 mg/kg b.w.) to induce colonic ACF. The colonic mucosa was examined for the total numbers of aberrant crypt (AC) and ACF after staining with methylene blue. The blood and serum were analyzed with a blood cell differential counter and an automatic serum analyzer. Iron-overloaded diet increased the concentration of iron in liver of the rats. But iron-related parameters in blood were not changed among experimental groups. The numbers of ACF per colon and AC per colon were $178.8{\pm}33.2$ and $448.4{\pm}110.2$ in the iron-overloaded F344 rats. The total AC was significantly increased, compared with normal-diet AOM control group (p < 0.05). The treatments of PA at the dose of 0.5% slightly decreased the number of ACF and AC per colon to $153.6{\pm}29.5$ and $396.3{\pm}107.5$. However, there were no significant differences in the total numbers of ACF and AC between the AOM control group and PA (0.5% or 2%)-treated groups. These results suggest that PA may not affect the formation of ACF or AC induced by AOM in ironoverloaded F344 rats.

• Animal cells and systems
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• 제13권2호
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• pp.105-112
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• 2009

In this study, the effects of iron on cytochrome c oxidase (CcO) in rat lung mitochondria were examined. Similar to liver mitochondria, iron accumulated considerably in lung mitochondria (more than 2-fold). Likewise, the reactive oxygen species and nitric oxide (NO) content of mitochondria were increased by more than 50% and 100%, respectively. NO might be produced by nitric oxide synthase (NOS), eNOS and iNOS type, with particular contribution by NOS in mitochondria. The respiratory control ratio of iron overloaded lung mitochondria dropped to nearly 50% due to increased state 4. Likewise, cytochrome c oxidase activity was lowered significantly to approximately 50% due to excess iron. Real-time PCR revealed that the expression of isoforms 1 and 2 of subunit IV of CeO was enhanced greatly under excess iron conditions. Taken together, these results show that oxidative phosphorylation within lung mitochondria may be influenced by iron overload through changes in cytochrome c oxidase and NO.

• 한국식품위생안전성학회지
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• 제23권3호
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• pp.264-270
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• 2008

대장암은 국민경제 수준의 향상과 식생활의 서구화에 따라 급격하게 증가하여, 등록환자 기준으로 2005년 현재 위암에 이어 두 번째로 많은 상태이다. 특히 육류에 많이 함유된 철분 및 지방의 과다섭취가 주요원인으로 여겨지고 있다. Phytic acid(PA) (Inositol hexaphosphate, IP6)는 식물의 박류, 콩류 등에 약 0.1-5% 농도로 존재하며, 포유류의 세포에서도 존재한다. PA는 금속이온과 결합하는 성질을 갖고 있어서, hydroxyl radical과 같은 활성산소종의 형성을 억제하여 항산화 작용을 나타낸다. 본 연구에서는 PA가 대장암 발생의 전암병변인 aberrant crypt faci(ACF) 의 발생을 억제하는지를 조사하고자 수컷 F344 랫드를 사용하였다. Azoxymethane(AOM)을 실험시작 1주 및 2번째 주에 투여함으로 ACF를 유발하였고, 실험기간은 8주로서 AIN-93G 사료급여와 동시에 음수로서 0.5%와 2% PA를 급여하였다. 부검 후, 혈액검사와 대장암 발생의 초기단계인 ACF를 측정하였다. 결과로서 AOM 투여 대조군과 비교해 볼 때 PA의 농도가 증가함에 따라 ACF와 aberrant crypt(AC)의 수가 감소하였고, 2% PA는 유의적으로 ACF와 AC의 수를 감소시켰으며, 더욱이 4개 이상 AC를 갖는 ACF의 수를 유의적으로 감소시켰다. 또한 혈액 생화학적 수치에서 어느 정도 유의적 변화가 나타났지만 정상범위내에서의 변화로서 인정될 수 있을 것이다. 본 실험에서 이러한 결과는 phytic acid가 대장암 발생과정에 전암병변의 형성을 억제함으로서 최종 대장암발생에 억제효과를 나타낼 수 있을 것이라 사료된다.