Influence of magnesium depletion on matrix-induced endochondral bone formation

Abstract

The effect of magnesium deficiency on bone cell differentiation and bone formation was investigated using in vivo matrix-induced endochondral ossification as a test system. Demineralized bone matrix was implanted subcutaneously in young (35-day-old) male Long-Evans rats that had been fed a semisynthetic Mg-deficient diet (50 ppm Mg) for 7 days. Plasma Mg levels were reduced to 25-30% of control values at that time. Control rats were paired the same diet, supplemented to contain 1000 ppm Mg. The implants were harvested 7, 9, 11, 15, and 20 days after implantation and analyzed for Mg and Ca content, 45Ca incorporation, and alkaline phosphatase levels. At each stage, plaques (implants) removed from Mg-deficient rats showed retardation in cartilage and bone differentiation and matrix calcification. Magnesium content was markedly reduced when compared to the control plaques. Histological appearance of the matrix-induced plaques confirmed the retardation in bone development and mineralization suggested by the chemical indicators. Most marked was the virtual absence of bone marrow in 20-day-old plaques in Mg-depleted rats. These data show that bone cell differentiation can occur in a severely Mg-depleted environment, although the onset of mineralization and bone remodeling was delayed and bone marrow differentiation was impaired.

Magnesium deficiency and osteoporosis: animal and human observations

“…Mg deficiency has also been observed to delay the onset of mineralization of newly formed cartilage matrix and bones [77]. Whether this is due to the effect on crystal formation or to some other process in mineralization is unclear.…”

Effects of a deficient magnesium supply during the dry period on bone turnover of dairy cows at parturition

“…Research concerning the effects of a low Mg supply on calcium (Ca) mobilisation of cows has shown that hypomagnesaemic cows had lower Ca mobilisation rates in response to hypocalcaemia induced by the intravenous infusion of disodium ethylenediaminetetra-acetate (Na2EDTA) than normomagnesaemic cows (4,7,30). In studies with rats it was found that the rates of bone mineralisation (12,32), bone formation (12) and bone resorption (12) in Mg-deficient rats were lower than in rats which had been fed adequate Mg. Histological examination of bones from Mg-deficient dogs showed a picture compatible with skeletal inactivity (8). These observations indicate that in Mgdeficient animals the rate of bone turnover is decreased.…”

An in vivo study on the metabolism and osteogenic activity of bioabsorbable Mg–1Sr alloy

“…It plays essential roles in metabolic pathways as an enzyme catalyst [16,17], in cell structure and function [18,19], and in bone formation and growth by promoting calcium deposition [20,21]. Although Mg is a highly electrochemically active anodic metal [13], advances in metallurgical alloy processing via phase design [13,22] and heat treatment [23] have opened avenues to address the rapid corrosion of Mg in order to meet clinical requirements.…”