Concurrent repletion of iron and zinc reduces intestinal oxidative damage in iron- and zinc-deficient rats
Concurrent repletion of iron and zinc reduces intestinal oxidative damage in iron- and zinc-deficient rats
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DOI：
10.3748/wjg.v13.i43.5707
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发表时间：
2007-11-21
影响因子：
4.3
通讯作者：
Krishnapillai, Madhavan Nair
中科院分区：
文献类型：
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作者：
Bodiga, Sreedhar;Krishnapillai, Madhavan Nair
目的：了解缺铁缺锌大鼠吸收过程中铁和锌的相互作用及其对肠道氧化-抗氧化平衡的影响。方法：24只断奶Wistar-京都大鼠，饲喂缺铁缺锌饲料(铁6.5 mg，锌4.0 mg/kg)4wk，随机分为3组，每组8只，分别给予铁4 mg、锌3.3 mg、铁4 mg+锌3.3 mg灌胃2wk。在最后一天，即动物处死前3h，给予37MBq的Fe-55或Zn-65，用显微放射自显影技术研究它们在肠道中的定位。测定血浆和肝脏中的血红蛋白、铁和锌含量，作为铁和锌状况的指标。十二指肠切片进行铁蛋白和金属硫蛋白免疫组织化学染色。结果：与单独补充铁或锌的大鼠相比，同时补充铁和锌的大鼠十二指肠匀浆中这些矿物质的定位减少；这些数据为拮抗相互作用提供了证据。这减少了脂肪和蛋白质氧化产物的形成，并改善了肠粘膜的功能完整性。此外，联合补充降低了铁相关乌头酸酶活性和铁蛋白的表达，但显著提高了肠粘膜中金属硫蛋白和谷胱甘肽的水平。联合补充过程中的相互作用及其后续作用的机制可能是通过调节胞浆乌头酸酶，进而影响不稳定的铁库和金属硫蛋白水平，从而减少肠道氧化损伤。结论：同时补充铁和锌纠正了铁和锌的缺乏，也减轻了与补铁相关的肠道氧化损伤。(C)2007年WJG。版权所有。
AIM: To understand the interactions between iron and zinc during absorption in iron- and zinc-deficient rats, and their consequences on intestinal oxidant-antioxidant balance.METHODS: Twenty-four weanling Wistar-Kyoto rats fed an iron- and zinc-deficient diet (< 6.5 mg Fe and 4.0 mg Zn/kg diet) for 4 wk were randomly divided into three groups (n = 8, each) and orally gavaged with 4 mg iron, 3.3 mg zinc, or 4 mg iron + 3.3 mg zinc for 2 wk. At the last day of repletion, 3 h before the animals were sacrificed, they received either 37 mBq of Fe-55 or Zn-65, to study their localization in the intestine, using microautoradiography. Hemoglobin, iron and zinc content in plasma and liver were measured as indicators of iron and zinc status. Duodenal sections were used for immunochemical staining of ferritin and metallothionein. Duodenal homogenates (mitochondrial and cytosolic fractions), were used to assess aconitase activity, oxidative stress, functional integrity and the response of antioxiclant enzymes.RESULTS: Concurrent repletion of iron- and zinc-deficient rats showed reduced localization of these minerals compared to rats that were teated with iron or zinc alone; these data provide evidence for antagonistic interactions. This resulted in reduced formation of lipid and protein oxidation products and better functional integrity of the intestinal mucosa. Further, combined repletion lowered iron-associated aconitase activity and ferritin expression, but significantly elevated metallothionein and glutathione levels in the intestinal mucosa. The mechanism of interactions during combined supplementation and its subsequent effects appeared to be due to through modulation of cytosolic aconitase, which in turn influenced the labile iron pool and metallothionein levels, and hence reduced intestinal oxidative damage.CONCLUSION: Concurrent administration of iron and zinc corrects iron and zinc deficiency, and also reduces the intestinal oxidative damage associated with iron supplementation. (C) 2007 WJG. All rights reserved.