The Migration of ³²P and ⁴⁵Ca Across Bone Under the Influence of 3 mA Direct Current

Abstract

A counter migration of ³²P but not of ⁴⁵Ca occurred across a diaphragm of bone subjected to 3 mA of direct current for 8 hrs in 0.01 M HEPES, 5.2% glucose, pH 7.30. It is postulated that these results reflect the affinity of an immobile negatively-charged matrix of bone for calcium, the presence of positively-charged phosphate-containing molecular species such as Ca₂H₂P0₄⁺, and the electroosmotic movement of water. Bone appeared to have a greater affinity for calcium than for phosphate ions at pH 7.30, in the presence or absence of a direct electrical current.