Giugliano R, Millward D J
Br J Nutr. 1984 Nov;52(3):545-60. doi: 10.1079/bjn19840122.
Male weanling rats were fed on diets either adequate (55 mg/kg), or severely deficient (0.4 mg/kg) in zinc, either ad lib. or in restricted amounts in four experiments. Measurements were made of growth rates and Zn contents of muscle and several individual tissues. Zn-deficient rats exhibited the expected symptoms of deficiency including growth retardation, cyclic changes in food intake and body-weight. Zn deficiency specifically reduced whole body and muscle growth rates as indicated by the fact that (a) growth rates were lower in ad lib.-fed Zn-deficient rats compared with rats pair-fed on the control diet in two experiments, (b) Zn supplementation increased body-weights of Zn-deficient rats given a restricted amount of diet at a level at which they maintained weight if unsupplemented, (c) Zn supplementation maintained body-weights of Zn-deficient rats fed a restricted amount of diet at a level at which they lost weight if unsupplemented (d) since the ratio, muscle mass: body-weight was lower in the Zn-deficient rats than in the pair-fed control groups, the reduction in muscle mass was greater than the reduction in body-weight. Zn concentrations were maintained in muscle, spleen and thymus, reduced in comparison to some but not all control groups in liver, kidney, testis and intestine, and markedly reduced in plasma and bone. In plasma, Zn concentrations varied inversely with the rate of change of body-weight during the cyclic changes in body-weight. Calculation of the total Zn in the tissues examined showed a marked increase in muscle Zn with a similar loss from bone, indicating that Zn can be redistributed from bone to allow the growth of other tissues. The magnitude of the increase in muscle Zn in the severely Zn-deficient rat, together with the magnitude of the total losses of muscle tissue during the catabolic phases of the cycling, indicate that in the Zn-deficient rat Zn may be highly conserved in catabolic states.
在四项实验中，雄性断奶大鼠被喂食锌含量充足（55毫克/千克）或严重缺乏（0.4毫克/千克）的日粮，日粮供应方式分为自由采食或限量采食。对生长速率以及肌肉和几个单独组织中的锌含量进行了测量。缺锌大鼠表现出预期的缺乏症状，包括生长迟缓、食物摄入量和体重的周期性变化。锌缺乏特别降低了全身和肌肉的生长速率，这体现在以下方面：(a) 在两项实验中，自由采食的缺锌大鼠的生长速率低于成对喂食对照日粮的大鼠；(b) 补充锌增加了限量采食日粮的缺锌大鼠的体重，若不补充锌，它们会维持在该体重水平；(c) 补充锌使限量采食日粮的缺锌大鼠的体重维持在若不补充锌就会减重的水平；(d) 由于缺锌大鼠的肌肉质量与体重之比低于成对喂食的对照组，肌肉质量的减少大于体重的减少。肌肉、脾脏和胸腺中的锌浓度得以维持，肝脏、肾脏、睾丸和肠道中的锌浓度与部分但并非所有对照组相比有所降低，而血浆和骨骼中的锌浓度则显著降低。在体重的周期性变化过程中，血浆中的锌浓度与体重变化速率呈反比。对所检查组织中的总锌进行计算表明，肌肉中的锌显著增加，骨骼中的锌则有类似程度的减少，这表明锌可以从骨骼中重新分配，以促进其他组织生长。严重缺锌大鼠肌肉中锌增加的幅度，以及体重循环分解代谢阶段肌肉组织总损失的幅度，表明在缺锌大鼠中，锌在分解代谢状态下可能高度保守。
