Han S, Qiao X, Simpson S, Ameri P, Kemp F W, Bogden J D
Department of Preventive Medicine and Community Health, UMDNJ-New Jersey Medical School, Newark 07103-2714, USA.
J Nutr. 1996 Jan;126(1):317-23. doi: 10.1093/jn/126.1.317.
The loss of adipose tissue during energy restriction may be accompanied by a loss of lean body mass, including bone mass. Because most of the body lead burden is in the skeleton, we studied the effects of weight loss on the concentrations of lead in bone, blood and several organs in rats with prior but not current lead exposure. Concentrations of the essential divalent metals calcium, copper, iron, magnesium and zinc were also determined for comparison with lead. Lead-exposed rats (n = 25) were randomly assigned to one of three treatment groups: weight maintenance (WM), moderate weight loss (MWL) or substantial weight loss (SWL). For the two last-named groups, food intake was restricted for 4 wk to 70 and 40% of that of the WM group. Lead concentrations did not differ significantly (ANOVA, P > 0.05) among the three groups for blood, brain and bone. Significantly higher liver lead concentrations were observed in the SWL rats than in the WM and MWL groups. In general, organ concentrations of calcium, copper, magnesium and zinc were either lower or did not differ in the groups losing weight compared with the WM group. In contrast, organ Iron concentrations of the SWL group were higher than those of the other groups except in brain where there were no significant differences. The total liver content of lead was highest in the SWL group, but the lead content of other organs did not differ among the treatment groups. The contents of calcium, copper, magnesium and zinc generally were lower in the MWL and SWL groups than in the WM group in the liver and some of the other organs. The results demonstrate that weight loss can increase the quantity and concentration of lead in the liver, even in the absence of continued lead exposure. The data also demonstrate considerable differences among organ divalent metals in response to weight loss.
能量限制期间脂肪组织的减少可能伴随着瘦体重的减少，包括骨量的减少。由于人体大部分铅负荷存在于骨骼中，我们研究了体重减轻对先前有铅暴露但当前无铅暴露的大鼠骨骼、血液和多个器官中铅浓度的影响。还测定了必需二价金属钙、铜、铁、镁和锌的浓度，以便与铅进行比较。将有铅暴露的大鼠（n = 25）随机分为三个治疗组之一：体重维持组（WM）、中度体重减轻组（MWL）或大幅体重减轻组（SWL）。对于后两个组，食物摄入量限制4周，分别为WM组的70%和40%。三组之间血液、大脑和骨骼中的铅浓度无显著差异（方差分析，P > 0.05）。观察到SWL组大鼠肝脏中的铅浓度显著高于WM组和MWL组。一般来说，与WM组相比，体重减轻组的钙、铜、镁和锌的器官浓度要么较低，要么无差异。相比之下，SWL组的器官铁浓度高于其他组，但大脑除外，大脑中无显著差异。SWL组肝脏中的铅总量最高，但各治疗组其他器官中的铅含量无差异。MWL组和SWL组肝脏及其他一些器官中的钙、铜、镁和锌含量通常低于WM组。结果表明，即使在没有持续铅暴露的情况下，体重减轻也会增加肝脏中铅的含量和浓度。数据还表明，各器官二价金属对体重减轻的反应存在相当大的差异。
