乳酸锌和葡萄糖酸锌的生物利用率比较

A COMPARATIVE STUDY ON THE BIOAVAILABILITY OF ZINC LACTATE AND ZINC GLUCONATE IN RATS

本研究以边缘性缺锌大鼠为动物模型，观察补充乳酸锌或葡萄糖酸锌以后，动物血清和组织中的锌含量变化，并计算了这两种锌化合物的相对生物利用率（ＲＢＡ）。实验动物共分为８组：正常对照、缺锌对照、补充乳酸锌和葡萄糖酸锌各３个剂量组（剂量按锌计分别为：２０、４０、８０ｍｇ／ｋｇ）。后６个补锌组均喂养低锌饲料一个月后再分别补充不同类型和不同剂量的锌化合物。结果表明，经一个月低锌饲料喂养后，大鼠血清、肝脏和骨骼中的锌含量均显著降低，呈现出体锌消耗趋势，毛锌改变不明显。在低锌饲料中加入两种锌化合物后，３个剂量组都观察到动物体内锌储备明显增加，血清锌、肝锌和骨锌测定结果都随给药剂量的增加而上升，且皆有很好的剂量一效应关系。变化曲线显示，乳酸锌比葡萄糖酸锌能更有效地恢复缺锌动物的锌储备。由血清锌、肝锌和骨骼锌变化曲线的斜率比值计算二者的相对生物利用率。分别为１．４１、１．５３和１．３４。实验大鼠对乳酸锌生物利用率约为葡萄糖酸锌的１．３～１．５倍。乳酸锌的分子量约为葡萄糖酸锌的一半，小分子量的配位体可能是增加锌吸收利用的有利因素。至于乳酸锌本身是否对锌的吸收有其它作用，尚待研究。

he bioavailability of zinc lactate and zinc gluconate were studied in ratsfed a soybean-based zinc deficient diet (ZD).After having been fed ZD dietfor one month the rats were divided into Six groups,three grouos were feddlets with 20, 40 and 80 mg/kg zinc supplemented as zinc lactate,the otherthree groups were fed same levels of zinc as gluconate, All animals werekilled after four weeks feeding and the zinc contents in serum,liver and bonewere determined. A slope一ratio bioassay model was used to calculate the relative bioavai一lability (RBA) of zinc lactate(zinc gluconate=1.0).The results showed thatthe RBA of zinc lactate was 1,41,1.53 and 1.34 in terms of zinc levels ofserum,liver and bone against the diet levels of zinc respectively. It is sug-gested that zinc lactate possessed a greater bioavailability in rats probablybecause of its smaller molecular weight.