Scientific Proceedings (113). 



Malates. 



Two rabbits received 12-33 daily doses (subcutaneous) of 

 0.1 6-1. 10 gm. per kg. of 4 per cent, di-sodium malate. Both 

 animals maintained a highly positive calcium balance. No 

 abnormal variations in the calcium content of the blood were 

 observed. Autopsy of one animal showed no macroscopic lesions 

 of the urinary system. 



Phosphates. 



Four rabbits received 5-34 daily doses (subcutaneous) of 

 0.16-0.5 1 S m - P er kg. of 4 per cent, di-sodium phosphate. All of 

 these animals maintained a highly positive calcium balance even 

 though two of them were on a much lower calcium intake. (Rab- 

 bit No. 5, 0.13-0. 16 gm. Ca per day; Rabbit No. 10, 0.17-0.31 gm. 

 Ca per day.) Five days after receiving the first injection of 

 phosphate, Rabbit No. 5 showed a decrease in the calcium content; 

 35 per cent, in whole blood and 28 per cent, in the plasma. Six 

 days after receiving the first phosphate injection, Rabbit No. 10 

 showed a marked decrease in the calcium content of blood (23.0 

 per cent.) and plasma (30 per cent.). The average of 8 deter- 

 minations during the injection period (35 days) showed a decrease 

 in the calcium content of 20 per cent, in whole blood and 26 per 

 cent, in plasma. 



An intermittent albuminuria was observed in all animals 

 receiving phosphates. 



Summary. 



1. Repeated subcutaneous injections of citrate, malate or 

 phosphate have no effect on the calcium balance of animals 

 receiving a calcium-rich diet. 



2. The calcium content of the blood -may be temporarily 

 decreased by the injection of large doses of citrate. 



3. Animals on a low calcium intake may, after phosphate injec- 

 tion, exhibit a decrease of 20-26 per cent, in the calcium content 

 of the blood and still maintain a positive calcium balance. This 

 observation emphasizes the suggestion that animals may adjust 

 themselves to different "calcium levels" just as is true of nitrogen. 



