Effects of vanadium (V) and magnesium (Mg) on rat bone tissue: mineral status and micromorphology. Consequences of V–Mg interactions

Abstract

The extent to which the 12 week separate and combined administration of vanadium (as sodium metavanadate – SMV, 0.125 mg V per ml) and magnesium (as magnesium sulphate – MS, 0.06 mg Mg per ml) affects bone mineral status and micromorphology as well as the alkaline phosphatase (ALP) activity in femoral diaphysis (FD) was examined in male rats. The bone chemical composition of SMV-exposed rats was also investigated. SMV alone or in combination with MS (as SMV–MS) reduced the levels of Mg_FD (by 21% and 20%) and P_FD (by 12% and 9%), lowered the Ca_FD content (by 7% and 10%), and caused a rise of the Fe_FD concentration (by 22.5% and 17%), compared with the control; SMV alone also reduced and enhanced the K_FD and Zn_FD concentrations (by 19% and 15%, respectively) but remained without significant effect on the femoral bone surface roughness (FBSR), whereas MS alone lowered the V_FD, P_FD, and Cu_FD levels (by 42%, 10%, and 20.6%), reduced FBSR, and created the regular femoral bone surface shape. The SMV–MS combination also induced a decline and rise in the levels of Cu_FD (by 30%) and Na_FD (by 15%), respectively, compared with the control and the MS-supplemented rats; elevated ALP_FD activity (by 24%, 35%, and 40%), compared with the control, SMV-exposed, and MS-supplemented animals; and increased FBSR. Relationships between the root mean square roughness (Sq) and skewness (Ssk): Sq [MS < SMV < Control < SMV–MS] ⇔ Ssk [SMV–MS > Control > SMV > MS], ALP_FD and Sq: ALP_FD ⇔ Sq [SMV–MS > Control > SMV > MS], and between other variables were demonstrated. A partial limitation of the drop in the P_FD and K_FD levels and normalization of the Zn_FD concentration were a consequence of the V–Mg antagonistic interaction whereas a consequence of the V–Mg synergistic interaction was the increase in the Na_FD level, ALP_FD activity, and FBSR. Ca₁₀(PO₄)₅(SiO₄)(OH) was part of the inorganic component of the bone of the SMV-exposed rats.