TRIGLYCERIDES AND FATTY ACIDS 123 



One g. fat = X 3 = 3.43 millimoles fatty acid 



874 



One g. protein N (from leucine, tyrosine) = 15 millimoles fatty acid 



In the case of fat, the figure of 3.43 is assumed on the basis of a single 

 ketone body per fatty acid residue for triolein (mol. wt. = 874). In deter- 

 mining the ketogenic figure for protein, the value of 15 millimoles per g. of 

 urine nitrogen is an estimated value by the use of which close checks be- 

 tween predicted and actual ketonuria can be demonstrated. 



On the other hand, the antiketogenic values were calculated in millimoles 

 as follows r^''*'' 2^^ 



1000 .„. , 



One g. glucose = = 5.56 millimoles glucose 



180 



1000 1 ^ _ .„. , , 



One g. fat = X ~ = 0.57 milhmole glucose 



874 2 



One g. urinary N = 3.0 g. glucose 



3600 .„. , 



3.6 g. glucose = = 20 millimoles glucose 



180 



The estimation of the antiketogenic substance from glucose in millimoles, 

 is based upon the molecular weight of 180 for this monosaccharide. In the 

 case of fat, the glucose equivalent is calculated on the basis that each fat 

 molecule gives rise to one-half of a glucose molecule from the glycerol 

 moiety. The calculation of the millimoles of glucose per g. of urinary ni- 

 tre ),<rcii is !)ascd upon the theoretical relationship of urinary glucose to uri- 

 nary nitrogen of 3.60: 1 which obtains in a fasting diabetic subject. 



Shaffer-*"' assumed that one molecule of glucose is able to cause the com- 

 plete oxidation of two molecules of fatty acid, and that all fatty acids in 

 e.vcess of this value are excreted as ketone bodies in the urine. In a large 

 number of experiments cited from the literature, in which the amount of 

 th(> several foodstuffs metal)olized was reported, the expected ketonuria 

 was calculated. Remark8,ble agreement between calculated and deter- 

 mined \'alues was recorded in a number of instances. 



Woodyatt-^** also employed calculations similar to those of Shaffer to 

 estimate ketonuria. However, instead of bemg based upon millimoles, 

 these \'alues were estimated on the basis of actual grams of the several 



"8 R. T. WooJyatt, Arch. Internal Med., 28, 125-141 (1921). 



