Schümann K, Haen E
Walther Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, Federal Republic of Germany.
Chronobiol Int. 1988;5(1):59-64. doi: 10.3109/07420528809078552.
Circadian variations in plasma iron levels were first reported in humans in 1937. Influences of the sleeping pattern and of plasma cortisol and adrenaline levels on these variations as well as the reproducibility of the phenomenon itself are discussed controversially in the literature. The influence of food intake, however, was not considered in most of the studies and is therefore subject of this investigation. Circadian plasma iron and plasma transferrin variations were determined in rabbits and compared under free access to food and under starvation (caecotrophy was not prevented). Population-mean-cosinor analysis of circadian plasma iron concentrations showed similar variations in the fed and starved condition (mesor: 116.6 micrograms/dl vs 118.1 micrograms/dl, acrophase 0752 hr vs 0728) except for a significant increase of the circadian amplitude under free access to food (30.9 micrograms/dl vs 22.3 micrograms/dl, P less than 0.05). There was no variation in plasma transferrin, which shows that 24 hr variations in plasma iron are not caused by modulation of plasma transferrin. These findings demonstrate a circadian rhythm for plasma iron, the amplitude of which is increased by food intake.
血浆铁水平的昼夜变化于1937年首次在人类中被报道。睡眠模式、血浆皮质醇和肾上腺素水平对这些变化的影响以及该现象本身的可重复性在文献中存在争议。然而，大多数研究并未考虑食物摄入的影响，因此这是本研究的主题。测定了兔子血浆铁和血浆转铁蛋白的昼夜变化，并在自由进食和饥饿（未防止盲肠食粪症）条件下进行了比较。对昼夜血浆铁浓度的总体均值-余弦分析显示，在进食和饥饿条件下有相似的变化（平均中值：116.6微克/分升对118.1微克/分升，高峰相位0752时对0728时），只是在自由进食条件下昼夜振幅显著增加（30.9微克/分升对22.3微克/分升，P<0.05）。血浆转铁蛋白没有变化，这表明血浆铁的24小时变化不是由血浆转铁蛋白的调节引起的。这些发现证明了血浆铁的昼夜节律，其振幅因食物摄入而增加。
