Department of Physiology, Faculty of Pharmacy and Faculty of Sport Sciences, University of Granada, Campus Universitario de Cartuja s/n, Granada, 18071, Spain.
Food Funct. 2014 Apr;5(4):716-23. doi: 10.1039/c3fo60525f. Epub 2014 Feb 17.
This study examined the effects of the dietary amount and source of protein on bone status in rats. 140 male Wistar rats aged 8 weeks were randomly allocated to 4 groups (n = 35) fed normal-protein (NP, 10% richness) or high-protein (HP, 45% richness) diets based on whey protein (WP) or soy protein (SP) sources for 12 weeks. Plasma urea was 46% higher for the HP compared to the NP diet (p < 0.001). Urinary calcium was 65% higher for the HP compared to the NP and 60% higher for the WP compared to the SP diets (all, p < 0.001). Urinary pH was 8% more acidic in the HP compared to the NP diet (p < 0.001) and 4% in the WP compared to the SP diet (p < 0.01). The plasma osteocalcin concentration was 19% higher for the NP compared to the HP (p < 0.05) and 25% for the SP compared to the WP diets (p < 0.01). Femur ash, metaphyseal and diaphyseal cross-sectional, trabecular and cortical areas were 3% higher in the HP compared to the NP diet (all, p < 0.05). Femur diaphyseal periosteal and endocortical perimeters were also 3% higher in the HP compared to the NP diet (both, p < 0.01). Groups fed the SP diet showed 2% higher femur ash percentage, 7% higher calcium content (both, p < 0.001), and 3% higher diaphyseal cortical area and thickness (both, p < 0.05) than those fed the WP diet. Some interactions were found, such as the greater effects of the SP diet on decreasing the higher plasma urea concentration promoted by the intake of the HP diet (p < 0.001). Under adequate Ca intake, HP diets could better maintain bone properties than NP diets, even with increasing some acidity markers, which could be reduced by the intake of SP sources.
这项研究旨在探讨不同蛋白质摄入量和来源对大鼠骨健康的影响。将 140 只 8 周龄雄性 Wistar 大鼠随机分为 4 组（n = 35），分别给予正常蛋白（NP，10%含量）或高蛋白（HP，45%含量）饮食，蛋白质来源分别为乳清蛋白（WP）或大豆蛋白（SP），喂养 12 周。与 NP 饮食相比，HP 饮食使大鼠的血浆尿素水平升高了 46%（p < 0.001）。与 NP 和 SP 饮食相比，HP 饮食使大鼠的尿钙排泄量分别增加了 65%和 60%（均 p < 0.001）。与 NP 饮食相比，HP 饮食使大鼠的尿 pH 值降低了 8%（p < 0.001），与 SP 饮食相比，尿 pH 值降低了 4%（p < 0.01）。与 HP 饮食相比，NP 饮食使大鼠的血浆骨钙素浓度升高了 19%（p < 0.05），与 SP 饮食相比，大鼠的血浆骨钙素浓度升高了 25%（p < 0.01）。与 NP 饮食相比，HP 饮食使大鼠的股骨灰分、骺端和骨干横截面积、骨小梁和皮质面积分别增加了 3%（均 p < 0.05）。与 NP 饮食相比，HP 饮食还使大鼠的股骨骨干骺端和皮质周径分别增加了 3%（均 p < 0.01）。与 WP 饮食相比，SP 饮食使大鼠的股骨灰分百分比增加了 2%，钙含量增加了 7%（均 p < 0.001），骨干皮质面积和厚度分别增加了 3%（均 p < 0.05）。研究还发现了一些相互作用，例如 SP 饮食对降低 HP 饮食引起的高血浆尿素浓度的作用更大（p < 0.001）。在充足的钙摄入条件下，HP 饮食可能比 NP 饮食更好地维持骨健康，尽管 HP 饮食增加了一些酸度标志物，但这些标志物可通过摄入 SP 来源来降低。
