~(41)Ca标记骨质疏松大鼠体内钙库法评价市售钙剂钙吸收率的研究

目的建立评价市售钙剂的钙吸收率方法。方法用去卵巢大鼠建立骨质疏松模型,41Ca标记大鼠体内钙库,原子吸收检测粪钙和血钙;以加速器质谱检测粪钙和血钙41Ca峰度。结果大鼠对该市售钙剂的表观吸收率为59.15%,净吸收率为69.18%,其中粪便内源钙占24.56%。结论41Ca标记体内钙库可得出净钙吸收率,且不受所评价的钙剂中钙的化学形式和种类的影响。此法能直接应用于市售钙剂钙吸收率的评价。

STUDY ON CALCIUM ABSORPTIVITY IN CALCIUM SUPPLEMENTS EVALUATED BY 41CA LABELED CALCIUM POOL OF OSTEOPOROTIC RATS

Objective To establish a evaluation method for absorptivity of marketed calcium supplements. Method The model of osteoporotic rats established by ovariectomy was labeled with 41Ca. The total calcium in biological samples was measured by flame atomic absorption spectrometry (FAAS) after microwave-digestion and 41Ca/40Ca was detected by accelerator mass spectrometry (AMS) by using CaF2 as target in Beijing HI-13 AMS system. Results The apparent absorptivity of calcium supplements was 59.15% ,the net absorptivity was 69.18% and endogenous calcium of total fecal calcium was 24.56% in the osteoporotic ovariectomic rats. Conclusion Using 41Ca labeled calcium pool in vivo could obtain the net calcium absorptivity without extrinsic labeling. Therefore, the method was not affected by the chemical structure and sorts of calcium supplements ,and might be used in evaluating absorptivity of marketed calcium supplements.