Ghio Andrew J, Schreinemachers Dina M
Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, Chapel Hill, NC, USA.
Biomark Insights. 2016 Apr 19;11:49-54. doi: 10.4137/BMI.S36226. eCollection 2016.
Heme oxygenase (HO) catalyzes the breakdown of heme to carbon monoxide, iron, and biliverdin. While the use of genetically altered animal models in investigation has established distinct associations between HO activity and systemic iron availability, studies have not yet confirmed such participation of HO in iron homeostasis of humans. Carbon monoxide produced through HO activity will bind to hemoglobin in circulating erythrocytes, and therefore, blood carboxyhemoglobin (COHb) can be used as an index of HO activity. Using the second National Health and Nutrition Examination Survey, we tested the postulate that HO activity correlates with serum indices of iron homeostasis in healthy nonsmokers. The investigation included 844 lifetime nonsmokers (586 females) 18 years of age and older in the study population. Significant correlations were demonstrated between COHb and several indices of iron homeostasis including serum levels of both ferritin and iron and percentage iron saturation of transferrin. There was no significant association between COHb and hemoglobin, the largest repository of heme in the human body, which functions as the substrate for HO. We conclude that HO activity contributes to human iron homeostasis with significant correlations between COHb and serum ferritin and iron levels and percentage iron saturation of transferrin.
血红素加氧酶（HO）催化血红素分解为一氧化碳、铁和胆绿素。虽然在研究中使用基因改造动物模型已确定HO活性与全身铁可用性之间存在明显关联，但尚未有研究证实HO参与人体铁稳态。通过HO活性产生的一氧化碳会与循环红细胞中的血红蛋白结合，因此，血液中的碳氧血红蛋白（COHb）可作为HO活性的指标。利用第二次全国健康和营养检查调查，我们检验了健康非吸烟者中HO活性与铁稳态血清指标相关的假设。该调查纳入了研究人群中844名18岁及以上的终生非吸烟者（586名女性）。结果表明，COHb与铁稳态的几个指标之间存在显著相关性，包括铁蛋白和铁的血清水平以及转铁蛋白的铁饱和度百分比。COHb与人体中最大的血红素储存库血红蛋白之间没有显著关联，血红蛋白是HO的底物。我们得出结论，HO活性有助于人体铁稳态，COHb与血清铁蛋白、铁水平以及转铁蛋白的铁饱和度百分比之间存在显著相关性。
