The Effects of Excessive Intake of Magnesium by the Rat; Especially concerning the Factors Relating to the Production of Renal Calculi

Abstract

1. Rats taken from mixed stock diet and fed synthetic diet containing an excess of magnesium carbonate developed urinary calculi in a large number of cases. 2. The incidence of calculi was much higher in the females. 3. Addition of excess of calcium carbonate to the diet prevented the formation of calculi. 4. Rats previously fed for a short time on the synthetic diet and normal salt mixture did not develop calculi, but suffered from severe catharsis. 5. Rats on mixed stock diet had a more acid caecum and colon than those on synthetic diet. 6. No significant alterations were found in the Ca, Mg or inorganic P of the blood on any of the diets. 7. Extra magnesium, or calcium, or sodium carbonate lowered the urinary phosphate excretion. 8. Extra magnesium or calcium had little effect upon the urinary excretion of the other, but tended in each case to lower the output. 9. Changes in the sex organs brought about by excessive intake of magnesium are described. The writer wishes to thank Miss V. E. Leader for her watchful care of the rats.