Background: Animal studies have demonstrated that iron may be related to carcinogenesis, and human studies found that heme iron can increase the formation of Nnitroso compounds, which are known carcinogens. Objectives...Background: Animal studies have demonstrated that iron may be related to carcinogenesis, and human studies found that heme iron can increase the formation of Nnitroso compounds, which are known carcinogens. Objectives: One of the postulated mechanisms linking red meat intake to cancer risk involves iron. Epidemiologic studies attempt to investigate the association between heme iron intake and cancer by applying a standard factor to total iron from meat. However, laboratory studies suggest that heme iron levels in meat vary according to cooking method and doneness level. We measured heme iron in meats cooked by different cooking methods to a range of doneness levels to use in conjunction with a food frequency questionnaire to estimate heme iron intake. Methods: Composite meat samples were made to represent each meat type, cooking method and doneness level. Heme iron was measured using atomic absorption spectrometry and inductively coupled plasma-atomic emission spectrometry. Results: Steak and hamburgers contained the highest levels of heme iron, pork and chicken thigh meat had slightly lower levels, and chicken breast meat had the lowest. Conclusions: Although heme iron levels varied, there was no clear effect of cooking method or doneness level. We outline the methods used to create a heme iron database to be used in conjunction with food frequency questionnaires to estimate heme iron intake in relation to disease outcome.展开更多
Iron deficiency is the most common nutritional deficiency leading to anemia in pregnancy. Conventionally, non-heme form of iron salts has been the mainstay of treatment. However, patient compliance is an important con...Iron deficiency is the most common nutritional deficiency leading to anemia in pregnancy. Conventionally, non-heme form of iron salts has been the mainstay of treatment. However, patient compliance is an important concern with existing oral iron therapy due to gastrointestinal side effects. Heme iron, a better bioavailable and tolerable form of iron can be suitable form of iron for supplementation in pregnancy. Evidence suggests its utility in pregnancy for treatment of iron deficiency anemia with benefits extending to postpartum period. Effective transfer across placenta to fetus further supports its utility in pregnancy. This review discusses in details the absorption kinetics along with clinical evidence on efficacy, safety, and tolerability of heme-iron supplementation in iron deficiency anemia of pregnancy.展开更多
AIM:To investigate the effects of the heme oxygenase(HO)-1/carbon monoxide system on iron deposition and portal pressure in rats with hepatic fibrosis induced by bile duct ligation(BDL).METHODS:Male Sprague-Dawley rat...AIM:To investigate the effects of the heme oxygenase(HO)-1/carbon monoxide system on iron deposition and portal pressure in rats with hepatic fibrosis induced by bile duct ligation(BDL).METHODS:Male Sprague-Dawley rats were divided randomly into a Sham group,BDL group,Fe group,deferoxamine(DFX) group,zinc protoporphyrin(ZnPP) group and cobalt protoporphyrin(CoPP) group.The levels of HO-1 were detected using different methods.The serum carboxyhemoglobin(COHb),iron,and portal vein pressure(PVP) were also quantified.The plasma and mRNA levels of hepcidin were measured.Hepatic fibrosis and its main pathway were assessed using Van Gieson's stain,hydroxyproline,transforming growth factor-β1(TGF-β1),nuclear factor-E2-related factor 2(Nrf2),matrix metalloproteinase-2(MMP-2) and tissue inhibitor of metalloproteinase-1(TIMP-1).RESULTS:Serum COHb and protein and mRNA expression levels of HO-1 and Nrf2 were increased in the BDL group compared with the Sham group and were much higher in the CoPP group.The ZnPP group showed lower expression of HO-1 and Nrf2 and lower COHb.The levels of iron and PVP were enhanced in the BDL group but were lower in the ZnPP and DFX groups and were higher in the CoPP and Fe groups.Hepcidin levels were higher,whereas superoxide dismutase levels were increased and malonaldehyde levels were decreased in the ZnPP and DFX groups.The ZnPP group also showed inhibited TGF-β1 expression and regulated TIMP-1/MMP-2 expression,as well as obviously attenuated liver fibrosis.CONCLUSION:Reducing hepatic iron deposition and CO levels by inhibiting HO-1 activity though the Nrf2/Keap pathway could be helpful in improving hepatic fibrosis and regulating PVP.展开更多
Iron deficiency is prevalent among endurance athletes, particularly females. Low iron may compromise oxygen delivery and physical performance. Vegetarianism, desire for convenience, and perceived health risks associat...Iron deficiency is prevalent among endurance athletes, particularly females. Low iron may compromise oxygen delivery and physical performance. Vegetarianism, desire for convenience, and perceived health risks associated with red meat contribute to low bioavailable iron intakes. The purpose of this study was to examine if lean beef supplementation would maintain iron status, improve body composition and increase performance of distance runners after 8 weeks. Twenty-eight (14 female) Division-I cross-country runners were stratified by iron status, use of iron supplements, and gender, and randomized into a control (n = 14) and intervention group. All participants maintained their typical diet and consumed a daily multivitamin, while the intervention group consumed 9 ounces of lean beef weekly. Dietary intake (total iron, heme-iron, protein, zinc), body composition, VO2max, and iron status (hemoglobin, hematocrit, serum iron, serum ferritin, total iron binding capacity [TIBC]) were measured at baseline and post-intervention. The intervention group had greater intakes of total and heme-iron. There were no group differences in amino acids, protein, or calories. Both groups had a significant body fat increase and lean mass decease over time. There was a significant VO2max increase over time in both groups. There were no group differences due to the intervention in serum ferritin, hemoglobin, serum iron, and TIBC. There was a significant difference in hematocrit between groups as a result of the intervention. In conclusion, increasing bioavailable iron from red meat may have effects on body composition and maintenance of blood iron markers;however, its direct impact on performance among endurance athletes is unclear.展开更多
AIM:To study the effect of both acute and chronic alcohol exposure on heme oxygenases(HOs) in the brain,liver and duodenum.METHODS:Wild-type C57BL/6 mice,heterozygous Sod2 knockout mice,which exhibit attenuated mangan...AIM:To study the effect of both acute and chronic alcohol exposure on heme oxygenases(HOs) in the brain,liver and duodenum.METHODS:Wild-type C57BL/6 mice,heterozygous Sod2 knockout mice,which exhibit attenuated manganese superoxide dismutase activity,and liver-specific ARNT knockout mice were used to investigate the role of alcohol-induced oxidative stress and hypoxia.For acute alcohol exposure,ethanol was administered in the drinking water for 1 wk.Mice were pair-fed with regular or ethanol-containing Lieber De Carli liquid diets for 4 wk for chronic alcohol studies.HO expression was analyzed by real-time quantitative polymerase chain reaction and Western blotting.RESULTS:Chronic alcohol exposure downregulated HO-1 expression in the brain but upregulated it in the duodenum of wild-type mice.It did not alter liver HO-1 expression,nor HO-2 expression in the brain,liver or duodenum.In contrast,acute alcohol exposure decreased both liver HO-1 and HO-2 expression,and HO-2 expression in the duodenum of wild-type mice.The decrease in liver HO-1 expression was abolished in ARNT+/-mice.Sod2+/-mice with acute alcohol exposure did not exhibit any changes in liver HO-1 and HO-2 expression or in brain HO-2 expression.However,alcohol inhibited brain HO-1 and duodenal HO-2 but increased duodenal HO-1 expression in Sod2+/-mice.Collectively,these findings indicate that acute and chronic alcohol exposure regulates HO expression in a tissue-specific manner.Chronic alcohol exposure alters brain and duodenal,but not liver HO expression.However,acute alcohol exposure inhibits liver HO-1 and HO-2,and also duodenal HO-2 expression.CONCLUSION:The inhibition of liver HO expression by acute alcohol-induced hypoxia may play a role in the early phases of alcoholic liver disease progression.展开更多
AIM To investigat the influence of hemochromatosis gene(Hfe) mutation on ^(59)Fe labelled duodenal heme absorption in mice.METHODS Heme absorption was measured in Hfe wild type and Hfe^((-/-)) mice by the duodenal tie...AIM To investigat the influence of hemochromatosis gene(Hfe) mutation on ^(59)Fe labelled duodenal heme absorption in mice.METHODS Heme absorption was measured in Hfe wild type and Hfe^((-/-)) mice by the duodenal tied loop and by oral gavage methods. The m RNA expression of heme oxygenase(HO-1), Abcg2 and Flvcr1 genes and levels were determined by quantitative polymerase chain reaction.RESULTS Heme absorption was significantly increased in homozygous Hfe^((-/-)) mice despite significant hepatic and splenic iron overload. While duodenal HO-1 mRNA was highly expressed in the wild type and Hfe^((-/-)) heme-treated group following 24 h heme administration, Flvcr1 a mRNA decreased. However, Abcg2 mRNA expression levels in duodenum remained unchanged. CONCLUSION Heme absorption was enhanced in Hfe^((-/-)) mice from both duodenal tied-loop segments and by oral gavage methods. HO-1 m RNA levels were enhanced in mice duodenum after 24 h of heme feeding and may account for enhanced heme absorption in Hfe^((-/-)) mice. Implications for dietary recommendations on heme intake by Hfe subjects to modulate iron loading are important clinical considerations.展开更多
In this paper, the kinetics of the interaction of the nitrosyl iron complex with the ligands penicillamine [Fe2(SC5H11NО2)2(NO)4]SO4·5H2O (I) with deoxyhemoglobin (Hb) was studied. The kinetic modeling met...In this paper, the kinetics of the interaction of the nitrosyl iron complex with the ligands penicillamine [Fe2(SC5H11NО2)2(NO)4]SO4·5H2O (I) with deoxyhemoglobin (Hb) was studied. The kinetic modeling method defined the number of binding (I) molecules and equilibrium constant of the coupling reaction of (Biomedicine, Iron-Sulfur Cluster, Ligand Binding, Heme, Nitric Oxide ) with Hb (Ks). At equimolar concentrations of (I) and Hb (2 × 10−5 M), the Hb molecule binds only one (I) with Ks equal to 4.3 × 107 M−1. When increasing the (Biomedicine, Iron-Sulfur Cluster, Ligand Binding, Heme, Nitric Oxide ) concentration, the number of binding sites of Hb increases and Ks decreases. These results are analyzed in accordance with the data on the existence of cations binding sites in Hb.展开更多
文摘Background: Animal studies have demonstrated that iron may be related to carcinogenesis, and human studies found that heme iron can increase the formation of Nnitroso compounds, which are known carcinogens. Objectives: One of the postulated mechanisms linking red meat intake to cancer risk involves iron. Epidemiologic studies attempt to investigate the association between heme iron intake and cancer by applying a standard factor to total iron from meat. However, laboratory studies suggest that heme iron levels in meat vary according to cooking method and doneness level. We measured heme iron in meats cooked by different cooking methods to a range of doneness levels to use in conjunction with a food frequency questionnaire to estimate heme iron intake. Methods: Composite meat samples were made to represent each meat type, cooking method and doneness level. Heme iron was measured using atomic absorption spectrometry and inductively coupled plasma-atomic emission spectrometry. Results: Steak and hamburgers contained the highest levels of heme iron, pork and chicken thigh meat had slightly lower levels, and chicken breast meat had the lowest. Conclusions: Although heme iron levels varied, there was no clear effect of cooking method or doneness level. We outline the methods used to create a heme iron database to be used in conjunction with food frequency questionnaires to estimate heme iron intake in relation to disease outcome.
文摘Iron deficiency is the most common nutritional deficiency leading to anemia in pregnancy. Conventionally, non-heme form of iron salts has been the mainstay of treatment. However, patient compliance is an important concern with existing oral iron therapy due to gastrointestinal side effects. Heme iron, a better bioavailable and tolerable form of iron can be suitable form of iron for supplementation in pregnancy. Evidence suggests its utility in pregnancy for treatment of iron deficiency anemia with benefits extending to postpartum period. Effective transfer across placenta to fetus further supports its utility in pregnancy. This review discusses in details the absorption kinetics along with clinical evidence on efficacy, safety, and tolerability of heme-iron supplementation in iron deficiency anemia of pregnancy.
基金Supported by Grants from the National Natural Science Foun-dation of China,No. 30970886The Science and Technology Project of Dalian,No. 2010E15SF179the Initial Doctoral funding of Liaoning Province,No. 20121110
文摘AIM:To investigate the effects of the heme oxygenase(HO)-1/carbon monoxide system on iron deposition and portal pressure in rats with hepatic fibrosis induced by bile duct ligation(BDL).METHODS:Male Sprague-Dawley rats were divided randomly into a Sham group,BDL group,Fe group,deferoxamine(DFX) group,zinc protoporphyrin(ZnPP) group and cobalt protoporphyrin(CoPP) group.The levels of HO-1 were detected using different methods.The serum carboxyhemoglobin(COHb),iron,and portal vein pressure(PVP) were also quantified.The plasma and mRNA levels of hepcidin were measured.Hepatic fibrosis and its main pathway were assessed using Van Gieson's stain,hydroxyproline,transforming growth factor-β1(TGF-β1),nuclear factor-E2-related factor 2(Nrf2),matrix metalloproteinase-2(MMP-2) and tissue inhibitor of metalloproteinase-1(TIMP-1).RESULTS:Serum COHb and protein and mRNA expression levels of HO-1 and Nrf2 were increased in the BDL group compared with the Sham group and were much higher in the CoPP group.The ZnPP group showed lower expression of HO-1 and Nrf2 and lower COHb.The levels of iron and PVP were enhanced in the BDL group but were lower in the ZnPP and DFX groups and were higher in the CoPP and Fe groups.Hepcidin levels were higher,whereas superoxide dismutase levels were increased and malonaldehyde levels were decreased in the ZnPP and DFX groups.The ZnPP group also showed inhibited TGF-β1 expression and regulated TIMP-1/MMP-2 expression,as well as obviously attenuated liver fibrosis.CONCLUSION:Reducing hepatic iron deposition and CO levels by inhibiting HO-1 activity though the Nrf2/Keap pathway could be helpful in improving hepatic fibrosis and regulating PVP.
文摘Iron deficiency is prevalent among endurance athletes, particularly females. Low iron may compromise oxygen delivery and physical performance. Vegetarianism, desire for convenience, and perceived health risks associated with red meat contribute to low bioavailable iron intakes. The purpose of this study was to examine if lean beef supplementation would maintain iron status, improve body composition and increase performance of distance runners after 8 weeks. Twenty-eight (14 female) Division-I cross-country runners were stratified by iron status, use of iron supplements, and gender, and randomized into a control (n = 14) and intervention group. All participants maintained their typical diet and consumed a daily multivitamin, while the intervention group consumed 9 ounces of lean beef weekly. Dietary intake (total iron, heme-iron, protein, zinc), body composition, VO2max, and iron status (hemoglobin, hematocrit, serum iron, serum ferritin, total iron binding capacity [TIBC]) were measured at baseline and post-intervention. The intervention group had greater intakes of total and heme-iron. There were no group differences in amino acids, protein, or calories. Both groups had a significant body fat increase and lean mass decease over time. There was a significant VO2max increase over time in both groups. There were no group differences due to the intervention in serum ferritin, hemoglobin, serum iron, and TIBC. There was a significant difference in hematocrit between groups as a result of the intervention. In conclusion, increasing bioavailable iron from red meat may have effects on body composition and maintenance of blood iron markers;however, its direct impact on performance among endurance athletes is unclear.
基金Supported by University of Nebraska Medical Center Funds and NIH grant (R01AA017738) to Harrison-Findik DD
文摘AIM:To study the effect of both acute and chronic alcohol exposure on heme oxygenases(HOs) in the brain,liver and duodenum.METHODS:Wild-type C57BL/6 mice,heterozygous Sod2 knockout mice,which exhibit attenuated manganese superoxide dismutase activity,and liver-specific ARNT knockout mice were used to investigate the role of alcohol-induced oxidative stress and hypoxia.For acute alcohol exposure,ethanol was administered in the drinking water for 1 wk.Mice were pair-fed with regular or ethanol-containing Lieber De Carli liquid diets for 4 wk for chronic alcohol studies.HO expression was analyzed by real-time quantitative polymerase chain reaction and Western blotting.RESULTS:Chronic alcohol exposure downregulated HO-1 expression in the brain but upregulated it in the duodenum of wild-type mice.It did not alter liver HO-1 expression,nor HO-2 expression in the brain,liver or duodenum.In contrast,acute alcohol exposure decreased both liver HO-1 and HO-2 expression,and HO-2 expression in the duodenum of wild-type mice.The decrease in liver HO-1 expression was abolished in ARNT+/-mice.Sod2+/-mice with acute alcohol exposure did not exhibit any changes in liver HO-1 and HO-2 expression or in brain HO-2 expression.However,alcohol inhibited brain HO-1 and duodenal HO-2 but increased duodenal HO-1 expression in Sod2+/-mice.Collectively,these findings indicate that acute and chronic alcohol exposure regulates HO expression in a tissue-specific manner.Chronic alcohol exposure alters brain and duodenal,but not liver HO expression.However,acute alcohol exposure inhibits liver HO-1 and HO-2,and also duodenal HO-2 expression.CONCLUSION:The inhibition of liver HO expression by acute alcohol-induced hypoxia may play a role in the early phases of alcoholic liver disease progression.
文摘AIM To investigat the influence of hemochromatosis gene(Hfe) mutation on ^(59)Fe labelled duodenal heme absorption in mice.METHODS Heme absorption was measured in Hfe wild type and Hfe^((-/-)) mice by the duodenal tied loop and by oral gavage methods. The m RNA expression of heme oxygenase(HO-1), Abcg2 and Flvcr1 genes and levels were determined by quantitative polymerase chain reaction.RESULTS Heme absorption was significantly increased in homozygous Hfe^((-/-)) mice despite significant hepatic and splenic iron overload. While duodenal HO-1 mRNA was highly expressed in the wild type and Hfe^((-/-)) heme-treated group following 24 h heme administration, Flvcr1 a mRNA decreased. However, Abcg2 mRNA expression levels in duodenum remained unchanged. CONCLUSION Heme absorption was enhanced in Hfe^((-/-)) mice from both duodenal tied-loop segments and by oral gavage methods. HO-1 m RNA levels were enhanced in mice duodenum after 24 h of heme feeding and may account for enhanced heme absorption in Hfe^((-/-)) mice. Implications for dietary recommendations on heme intake by Hfe subjects to modulate iron loading are important clinical considerations.
文摘In this paper, the kinetics of the interaction of the nitrosyl iron complex with the ligands penicillamine [Fe2(SC5H11NО2)2(NO)4]SO4·5H2O (I) with deoxyhemoglobin (Hb) was studied. The kinetic modeling method defined the number of binding (I) molecules and equilibrium constant of the coupling reaction of (Biomedicine, Iron-Sulfur Cluster, Ligand Binding, Heme, Nitric Oxide ) with Hb (Ks). At equimolar concentrations of (I) and Hb (2 × 10−5 M), the Hb molecule binds only one (I) with Ks equal to 4.3 × 107 M−1. When increasing the (Biomedicine, Iron-Sulfur Cluster, Ligand Binding, Heme, Nitric Oxide ) concentration, the number of binding sites of Hb increases and Ks decreases. These results are analyzed in accordance with the data on the existence of cations binding sites in Hb.
