Mineral bone composition and some elements of calcium metabolism in magnesium-deficient growing rats

1) Magnesium deficiency was induced in Sprague-Dawley male rats studied with pair-fed controls. The animals were killed after 10, 22 or 30 days of treatment. (2) The plasma composition of deficient subjects was characterized by : hypomagnesemia, slight hypercalcemia, hypophosphatemia, normal glycemia. Urinary hydroxyprolin decreased in deficient subjects after 21 and 29 days of deprivation. (3) The leg bones were fragmented as shown in figure Their magnesium content had decreased considerably and they were heavier. These two changes were especially marked in the metaphysis, were moderate in the epiphysis and less in the diaphysis. ( (5) Lower bone catabolism seemed to be mainly related to lower bone magnesium, and not to plasma magnesium. Increase in bone weight appeared to be a result of lower catabolism. The interpretation of calcic metabolism changes is discussed.