Münzenberg KJ, Meßler JGJ, Classen HG

Bonn/Hohenheim-Stuttgart

In the skeleton all alkaline earth metals follow the same distribution pattern; differences are maily due to their
position within the II. main group of the periodic system. The smaller ion radius of magnesium (Mg) compared
to calcium (Ca) implicates that Mg can substitute for Ca only insufficiently and hence is concentrated mostly in
the hydration shell; the consequences of Mg deficiency are mainly due to metabolic disturbances. Strontium
(Sr), due to its larger ion radius compared to Ca, cannot replace Ca by 1:1 in the crystal lattice, however
radiographically it feigns, e. g. following therapeutic application, a higher bone stock quantity of up to 10%
which can be calculated. In bone mean residence time amounts to 1,430 days for Mg; 2,850 days for Sr and
3,850 days for Ca. The Mg/Ca quotient of equal to or above 0,2 is of special importance in plasma and
interstitial fluid inhibiting the formation of crystalline calciumphosphate (apatite), that means of calcification.
Sr does not possess this characteristic trait.

JGJ Meßler: Zum Einfluss von Strontium auf die Knochendichtemessung und das Knochenmineral in vivo.
Dissertation, Bonn, 2015.
Rote-Hand-Brief zu Protelos^® (Strontiumranelat) vom 10.03.2014