Research Center for Food and Development (CIAD), Km 0.6 a La Victoria, Hermosillo, Sonora 83304, Mexico.
Technological Institute of Veracruz, UNIDA, Calzada Miguel Ángel de Quevedo 2779, Veracruz, Veracruz 91897, Mexico.
Nutrients. 2014 Jun 11;6(6):2229-39. doi: 10.3390/nu6062229.
Zinc homeostasis is achieved after intake variation by changes in the expression levels of zinc transporters. The aim of this study was to evaluate dietary intake (by 24-h recall), absorption, plasma zinc (by absorption spectrophotometry) and the expression levels (by quantitative PCR), of the transporters ZIP1 (zinc importer) and ZnT1 (zinc exporter) in peripheral white blood cells from 24 adolescent girls before and after drinking zinc-fortified milk for 27 day. Zinc intake increased (p < 0.001) from 10.5 ± 3.9 mg/day to 17.6 ± 4.4 mg/day, and its estimated absorption from 3.1 ± 1.2 to 5.3 ± 1.3 mg/day. Mean plasma zinc concentration remained unchanged (p > 0.05) near 150 µg/dL, but increased by 31 µg/dL (p < 0.05) for 6/24 adolescents (group A) and decreased by 25 µg/dL (p < 0.05) for other 6/24 adolescents (group B). Expression of ZIP1 in blood leukocytes was reduced 1.4-fold (p < 0.006) in group A, while for the expression of ZnT1 there was no difference after intervention (p = 0.39). An increase of dietary zinc after 27-days consumption of fortified-milk did not increase (p > 0.05) the plasma level of adolescent girls but for 6/24 participants from group A in spite of the formerly appropriation, which cellular zinc uptake decreased as assessed by reduction of the expression of ZIP1.
锌稳态是通过锌转运体表达水平的变化来实现的，这种变化是在摄入变化后产生的。本研究的目的是评估 24 名青春期女孩在饮用强化牛奶 27 天后，外周血白细胞中锌的摄入量（通过 24 小时回忆法）、吸收（通过吸收分光光度法）、血浆锌（通过定量 PCR）和转运体 ZIP1（锌内流）和 ZnT1（锌外流）的表达水平。锌的摄入量从 10.5 ± 3.9 mg/天增加到 17.6 ± 4.4 mg/天（p < 0.001），估计吸收量从 3.1 ± 1.2 mg/天增加到 5.3 ± 1.3 mg/天。平均血浆锌浓度保持不变（p > 0.05），接近 150 µg/dL，但有 6/24 名青少年（A 组）的血浆锌浓度增加了 31 µg/dL（p < 0.05），而其他 6/24 名青少年（B 组）的血浆锌浓度则降低了 25 µg/dL（p < 0.05）。A 组血液白细胞中 ZIP1 的表达减少了 1.4 倍（p < 0.006），而 ZnT1 的表达在干预后没有差异（p = 0.39）。在饮用强化牛奶 27 天后，膳食锌的增加并没有增加青春期女孩的血浆锌水平（p > 0.05），但对于 A 组的 6/24 名参与者来说，尽管之前已经吸收了锌，但血浆锌水平还是增加了，这是因为细胞内锌的摄取减少，表现为 ZIP1 表达减少。
