172 



Scientific Proceedings (120). 



firmatory experiments undertaken by Hess 1 led to the conclusion 

 that during the period of active rickets in children , the inorganic 

 phosphate of the blood is reduced, and that during the process of 

 cure by either sunlight or cod-liver oil, the phosphate rises again 

 to its normal level. 



Since the experimental rickets produced in rats is comparable 

 in most important respects to human rickets, it was thought of 

 interest to determine whether the same changes in blood phosphate 

 could be demonstrated in rats. In applying the work of Howland 

 and Kramer to experimental rat rickets, we have obtained results 

 which on the whole agree very well with those of theirs reported 

 at a recent meeting of the Society of Biological Chemists. 



Because of the small quantities of blood which can be obtained 

 from the animals, it seemed advisable to make the determinations 

 on whole blood rather than plasma if possible. Experiments 

 undertaken to show the relative distribution of the inorganic 

 phosphate in plasma and whole blood indicate that the level of the 

 phosphate is practically the same inside and outside the cells and is 

 maintained at a constant level from day to day. Therefore, as 

 far as the inorganic phosphate is concerned, it is immaterial 

 whether the determinations are made on whole blood or plasma. 

 (By the colorimetric method of Bell and Doisy. 2 ) 



Table I shows average figures for the inorganic phosphate in 

 theb lood of rats on rickets-producing, normal and high phosphorus 

 diets. 



table 1. 

 Inorganic Phosphate of Rat's Blood. 

 Inorganic Phosphate as Mgs. P per 100 c.c. Whole Blood. 



Diet. 



No. 

 of 

 Rats. 



Deter- 

 mina- 

 tions. 



Rickets. 



Blood 

 Phosphate. 



No. 



% P. 



% Ca. 



Max. 



Min. 



Av. 



Norm.. 





? 



55 



43 



None in 95 % 



8.2 



5-i 



6.2 



84 



86 



550 



40 



18 



Marked in 100% 



4.9 



2.0 



32 



D 



72 



380 



10 



7 



Marked in 100% 



5-0 



2-3 



3-5 



«5 



160 



550 



7 



2 



SI. osteoporosis 



5-5 



5-3 



5-4 



E 



120 



380 



16 



. 14 



SI. rickets in 25% 



74 



3-1 



6.1 



85 c... 



596 



020 



16 



6 



Mod. atypical ric. 



7.6 



6.0 



6.6 



F 



596 



015 



12 



9 



Mod. atypical ric. 



9.8 



6-5 



8.4 



G 



310 



550 



3 



3 



None 



9.8 



9.4 



9-6 



1 Hess, A. F., and Gutman, P., Proc. Soc. Exper. Biol, and Med., 1921, xix, 31. 



2 Bell and Doisy, J. Biol. Chcm. 1920, xliv, 55. 



