Rimbach G, Walter A, Most E, Pallauf J
Institute of Animal Nutrition and Nutrition Physiology, Justus-Liebig-University, Giessen, Germany.
Food Chem Toxicol. 1998 Jan;36(1):7-12. doi: 10.1016/s0278-6915(97)00117-8.
This study evaluated the effect of increasing levels of dietary microbial phytase on the bioavailability of zinc and the accumulation of cadmium and lead in growing rats. Five groups of seven albino rats (initial average weight 47 g) were housed individually and fed phytate-rich diets (7 g/kg) based on maize, soya bean meal, corn starch and soya bean oil over a 4-week experimental period. The basal diet contained 24 mg zinc (native concentration), 10 mg lead as Pb(CH3COO)2.3H2O and 5 mg cadmium as CdCl2 per kg and was supplemented with 0, 250, 500, 1000 and 2000 U phytase from Aspergillus niger per kg diet. Supplementation of microbial phytase significantly increased apparent zinc absorption. Differences in zinc bioavailability due to supplementation of the diet with microbial phytase were evident in zinc concentration in plasma, femur and testes as well as in the percentage unsaturated plasma zinc binding capacity and the activity of the zinc metalloenzyme alkaline phosphatase. Cadmium concentrations in liver and kidneys were not significantly altered in response to the different dietary treatments. There was a tendency for femur lead concentration to be increased in response due to the phytase supplementation.
本研究评估了日粮中微生物植酸酶水平升高对生长大鼠锌生物利用率以及镉和铅蓄积的影响。将五组每组七只白化大鼠（初始平均体重47克）单独饲养，并在为期4周的实验期内，基于玉米、豆粕、玉米淀粉和大豆油，饲喂富含植酸盐的日粮（7克/千克）。基础日粮每千克含有24毫克锌（天然浓度）、10毫克以Pb(CH3COO)2·3H2O形式存在的铅和5毫克以CdCl2形式存在的镉，并分别添加每千克日粮0、250、500、1000和2000单位来自黑曲霉的植酸酶。补充微生物植酸酶显著提高了锌的表观吸收率。日粮添加微生物植酸酶导致的锌生物利用率差异在血浆、股骨和睾丸中的锌浓度、不饱和血浆锌结合能力百分比以及锌金属酶碱性磷酸酶的活性方面均很明显。肝脏和肾脏中的镉浓度对不同日粮处理没有显著变化。由于添加植酸酶，股骨铅浓度有升高的趋势。
