Kuhn I, Jost V, Wieckhorst G, Theiss U, Lücker P W
Institut für klinische Pharmakologie Bobenheim, FRG.
Methods Find Exp Clin Pharmacol. 1992 May;14(4):269-72.
Magnesium is an important cation in human physiology, especially in the regulation of membrane proteins, as a cofactor for various enzyme systems and in neuromuscular transmission. Magnesium deficiency leads to severe impairment in muscle function, particularly in cardiovascular diseases. Classical bioavailability studies with magnesium cannot be carried out for several reasons. As the magnesium concentration in plasma is extraordinarily well regulated, renal elimination proves to be the best method to determine the absorption of orally administered magnesium. Magnesium pools must first be filled, and the saturation phase of renal elimination then equals the degree of absorption. This parameter of bioavailability shows the percentage of eliminated magnesium in comparison to the administered dose. Eighteen healthy male volunteers were included in this study to compare 5 mg magnesium-DL-hydrogen aspartate with magnesium-L-hydrogen aspartate. After a saturation phase, the test substances were administered in random order. Blood samples for determination of magnesium concentrations were taken, but no typical pharmacokinetic concentration curves were obtained. The areas under the concentration-time curves were equal for both formulations (x = 40.22 [mval*h/l]). The bioavailability of both substances was determined from the renal elimination. No significant difference was found between both treatments. Bioavailability of 5 mg magnesium-DL-hydrogen aspartate was 44.5% and for magnesium-L-hydrogen aspartate 41.7%. It is evident that this method of magnesium determination is practical, comfortable for volunteers and gives reliable results in comparing the absorption of magnesium formulations.
镁是人体生理学中的一种重要阳离子，特别是在膜蛋白调节、作为各种酶系统的辅助因子以及神经肌肉传递方面。镁缺乏会导致肌肉功能严重受损，尤其是在心血管疾病中。由于多种原因，无法进行经典的镁生物利用度研究。由于血浆中的镁浓度受到非常良好的调节，肾脏排泄被证明是确定口服镁吸收的最佳方法。必须首先填充镁池，然后肾脏排泄的饱和阶段等于吸收程度。这种生物利用度参数显示了与给药剂量相比排泄的镁的百分比。本研究纳入了18名健康男性志愿者，以比较5毫克DL-氢天冬氨酸镁和L-氢天冬氨酸镁。在饱和阶段后，以随机顺序给予受试物质。采集血样以测定镁浓度，但未获得典型的药代动力学浓度曲线。两种制剂的浓度-时间曲线下面积相等（x = 40.22 [mval*h/l]）。两种物质的生物利用度通过肾脏排泄来确定。两种治疗之间未发现显著差异。5毫克DL-氢天冬氨酸镁的生物利用度为44.5%，L-氢天冬氨酸镁为41.7%。很明显，这种镁测定方法实用、对志愿者来说舒适，并且在比较镁制剂的吸收方面能给出可靠的结果。
