18. 低マグネシウ厶高リン食摂取KKマウスに引き起こされる軟部組織石灰化と高リン酸血症

抄録

Severe cardiac calcification developed spontaneously in hereditarily diabetic KK mice maintained on a stock diet. Feeding the mice upon purified diets with various mineral compositions caused two types of acute and reproducible calcification. In the first type of calcificatiori, which was induced by a diet low in magnesium and high in phosphorus, the heart and kidney were most severely affected and the calcium contents of the tissues were elevated to about 300- and 100-fold of the normal levels at 10 days of the feeding, respectively. The rapid increase of tissue calcium level was first recognized in the kidney with a simultaneous rise in plasma inorganic phosphorus after 24 hours on the diet. Addition of magnesium or reduction of phosphorus in the diet completely prevented the development of a11 these changes. Another type of experimental calcification, induced by diets low in magnesium, phosphorus and calcium, was characterized primarily by cardiac calcification and by the absence of renal calcification. Both calcifications induced spontaneously and by diet were not recognized in ICR, C57BL and CF1 mice. The present findings suggest that relative deficiency in magnesium is mainly responsible for development of the tissue calcifications in KK mice.