The effect of magnesium deficiency on phosphatase activity and bone
composition was determined in the femora of young rats. In the right distal
metaphysis the acid and alkaline phosphatase activities were decreased in
magnesium-deficient rats, and the activity of bone alkaline phosphatase in
the incubation mixture after adding magnesium was significantly greater in
the magnesium-deficient than in the control rats. In the left distal
metaphysis the water content was significantly lower in the
magnesium-deficient rats at the fifth week but not at the third week.
Conversely, the ash content of metaphyseal bone was significantly increased
in magnesium-deficient rats at the fifth week, but not at the third week.
The magnesium and phosphorus contents were abnormally low in the deficient
bone at both periods. The calcium content was increased in the deficient
bone at the third week, but not at the fifth week.