Aorta and Other Soft Tissue Calcification in the Magnesium-deficient Rat

Abstract

Soft tissue calcification in the rat as induced by magnesium deficiency was studied with the emphasis on aorta calcification. In experiment 1 supplementation of the basal diet (80 ppm Mg) with 20 or 40 ppm magnesium permitted survival, yet induced kidney, heart and aorta calcification. A decrease in the aorta uptake of glycine-1-¹⁴C was also found. Experiment 2 showed a decrease in the elastin content of the aorta, a decreased aorta elastin glycine-1-¹⁴C uptake and an increase in the aorta elastin calcium content in rats fed the magnesium-deficient basal diet supplemented with 20 ppm magnesium. In experiment 3 restricted feeding of the magnesium-adequate diet (1000 ppm Mg added) did not alter the tissue calcium levels, percentage of aorta elastin, or aorta elastin calcium content when compared with magnesium-adequate ad libitum-fed rats. These experiments indicate that elastin is the site of calcification in magnesium deficiency and that the metabolism of the aorta elastin is altered.