抗性淀粉对大鼠锌营养状况的影响

EFFECTS OF RESISTANT STARCH ON ZINC STATUS IN RATS

目的 : 研究抗性淀粉 ( RS)对大鼠锌营养状况的影响。方法 : ( 1 )正常大鼠锌代谢 :3组 Wistar大鼠分别用基础饲料 (对照组 )、含有 1 3%或 2 6% RS的饲料喂养 1 8d,收集尿样、粪样 ,及血样 ,测定锌含量 ,计算锌表观吸收率。 ( 2 )高糖 ( 5 0 % )饮食大鼠锌营养状况 :3组 Wistar大鼠分别用基础饲料、高糖淀粉饲料 ( S- DS)及高糖抗性淀粉饲料 ( S- RS,含 1 4% RS)喂养 1 2 w。收集尿样 ,血样、肝脏、胰脏、肾脏等样品 ,测定锌含量。结果 : ( 1 )正常大鼠锌表观吸收率分别为 :对照组 5 6.5 9% ,1 3% RS组 5 0 .1 1 %及 2 6% RS组 5 4 .40 %。 ( 2 )高糖饲料使 S- DS组大鼠餐后血糖和糖化血红蛋白升高 ,空腹胰岛素水平降低 ;血锌和胰脏锌显著低于对照组 ( P<0 .0 5 )。 S- RS组血糖状态正常 ,尿锌排出低于 S- DS组 ,红细胞锌高于 S- DS组 ,且肾锌增高 ( P<0 .0 5 )。结论 : RS不影响正常大鼠锌表观吸收率 ,却可通过调节血糖维持高糖饮食大鼠锌营养状况。

Objective: To investigate the specific effects of resistant starch (RS) on zinc status in rats. Methods: (1)Zinc metabolism in normal rats: Three groups of Wistar rats were fed with basal diet (control), diet with 13% or 26% RS respectively, for 18 days. Urine, fecal and blood samples were collected for zinc measurement. Zinc apparent absorption was calculated.(2)Zinc status in rats fed with high sucrose (50%) diet: Three groups of Wistar rats were fed with basal diet, high sucrose digestible starch diet (S DS) or high sucrose resistant starch diet (S RS, containing 14% RS) respectively for 12 w. Samples of urine, blood, liver, pancreas and kidney were collected for measurement of zinc content. Results: (1)Zinc apparent absorption in normal rats was: control group 56.59%, 13%RS group 50.11%, and 26%RS group 54.40%. (2)High sucrose diet led to increased postprandial glucose and HbA 1C and depressed fast insulin level in S DS group rats, with decreased plasma and pancreas zinc level (compared with control group, P<0.05). In S RS group, the rats were of normal blood glucose status, with lower urine excretion and higher erythrocyte zinc level compared with S DS group (P<0.05). High kidney zinc was detected in S RS group. Conclusion: RS has no effect on zinc apparent absorption in normal rats. But for the rats fed with high sucrose diet, RS is of potential benefit to maintenance of zinc status.