The Ca/Mg ratio in fibrous connective tissue may be related to its ela
stic property. Ligamenta flava were obtained from 76 patients during l
umbar disc surgery, and Ca and Mg levels were determined by atomic abs
orption spectrometry. The Ca/Mg ratio was almost constant throughout a
ll age groups. It is concluded that the constancy of the Ca/Mg ratio t
hroughout the lifetime is an integral quality of elastic fibers which
may be explained by the biological long half-life of elastin.