Iron (Fe) is an essential metal in biological processes, which maintains a homeostasis in the human body Divalent metal transporter I (DMTI) has been known as an iron transporting membrane protein, which is involved in the uptake Fe at the apical portion of intestinal epithelium, and may transport Fe across the membrane of acidified endosome in peripheral tissues In this study, we studied the tissue distribution of DMT1 in the Fe supplemented (FeS) diet fed rats, and the regulation of DMT1 expression by depleting body Fe Sprague-Dawley rats were divided into two groups, and fed FeS (120 mg Fe/kg) diet or Fe deficient (FeD, 2~6 mg Fe/kg) diet for 4 weeks The evaluation of body Fe status was monitored by measuring sFe, UIBC and tissue Fe concentration Additionally, DMT1 mRNA levels were analyzed in the peripheral tissues by using the quantitative real time RT-PCR method In the FeS diet fed rats, the tissue Fe was maintained at a relatively high level, and DMT1 was eventually expressed in all tissue studied DMT1 was highly expressed in the testis, kidney and spleen, while a moderate levels of DMT1 expression was detected in the brain, liver and heart In the digestive system, the highest level ot DMTI was found In the duodenum Feeding the FeD diet caused a reduced body weight gam and depletion of body Fe with finding of decieated sFe, increased UlBC and decreased tissue Fe concentration The depletion of body Fe upregulated DMT1 expression in the peripheral tissue The expresstion of DMT1 was very sensitive to the body Fe depletion in the small intestine, especially m the duodenum, showing dramatically higher levels in the FeD rats than those of the FeS group In the FeD diet fed ammals the expression of DMT1 was low significantly In other tissues compared with the duodenum The expression of DMT1, however, was 60~120% higher in the testis, kidney and spleen, and 30 ~50% higher in the lung, liver and heart, compared to the PeS diet fed rats In summary, DMT1 expression was ubiquitous in mammalian tissue, and the level of expression was the organ-dependent The expression of DMT1 In peripheral tissues was upregulated by depletion of body Fe Duodenum was the most sensitive tissue among organs studied during Fe depletion, and expressed the greatest level of DMT1, while other tissues were less higher than in duodenum This study supports that DMT1 plays a role in maintaining the body Fe level through intestinal uptake as well as homeostasis of Fe in the peripheral tissue
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