Mahoney J P, Small W J
J Clin Invest. 1968 Mar;47(3):643-53. doi: 10.1172/JCI105760.
The biological half-life of manganese and some factors influencing it have been studied in man. The disappearance of manganese from the body in normal subjects is described by a curve having two exponential components. An average of 70% of the injected material was eliminated by the "slow" pathway. The half-time characterizing this component showed a small variation in normal subjects and had an average value of 39 days. The half-time for the "fast" component also showed a small variation and had an average value of 4 days. In a normal subject presumed to have a low manganese intake due to a voluntary low caloric intake, the percentage eliminated by the slow pathway increased to 84% and the half-time characterizing the pathway increased to 90 days. The half-time of the "fast" component was the same as for the normal group. 2 months after initiation of the study in this subject, a large "flushing" dose of manganese markedly increased the elimination rate which was described by a single exponential curve.A mildly iron-deficient subject showed a marked decrease in the percentage of manganese eliminated by the "slow" pathway accompanied by a less dramatic decrease in the half-time characterizing this pathway. Oral iron therapy, which corrected the mild anemia, caused a decrease in the elimination rate and the altered curve was described by a single exponential component. Preloading two subjects with manganese resulted in a great decrease in the fraction eliminated by the "slow" pathway with less effect on the half-time. The subject with the largest preloading dose showed no "slow" component at all. Observations on the red cells of some of these subjects showed that a small but definite fraction was incorporated into the erythrocytes. In the mildly iron-deficient subject, our observations suggest an interrelationship between manganese and iron metabolism.
锰的生物半衰期及其一些影响因素已在人体中进行了研究。正常受试者体内锰的消失情况由一条具有两个指数成分的曲线描述。注入物质的平均70%通过“慢速”途径消除。表征该成分的半衰期在正常受试者中变化较小，平均值为39天。“快速”成分的半衰期也有较小变化，平均值为4天。在一名因自愿低热量摄入而被认为锰摄入量低的正常受试者中，通过慢速途径消除的百分比增加到84%，表征该途径的半衰期增加到90天。“快速”成分的半衰期与正常组相同。在该受试者开始研究2个月后，大剂量的“冲击性”锰显著提高了消除率，其由一条单一指数曲线描述。一名轻度缺铁的受试者通过“慢速”途径消除的锰百分比显著下降，同时表征该途径的半衰期也有不太明显的下降。纠正轻度贫血的口服铁疗法导致消除率下降，变化后的曲线由一个单一指数成分描述。给两名受试者预先加载锰导致通过“慢速”途径消除的部分大幅减少，而对半衰期的影响较小。预先加载剂量最大的受试者根本没有“慢速”成分。对其中一些受试者红细胞的观察表明，有一小部分但确定的量被结合到红细胞中。在轻度缺铁的受试者中，我们的观察结果表明锰与铁代谢之间存在相互关系。
