INTERMEDIATE METABOLISM OF THE FATS 409 



and that in diabetics, through failure of a particular tissue, namely 

 the islets of Langerhans in the pancreas, the further stages of oxidation 

 are hindered, just as, in asphyxia, the oxidations of carbohydrates 

 subsequent to the production of lactic acid are hindered. The appear- 

 ance of abnormal quantities of Cholesterol in the blood of diabetics 

 suggests the possibility that the metabolism of the Hydroxyaromatic 

 Derivatives is also disordered in diabetics. The other u acetone- 

 bodies" in diabetic urine are undoubtedly derived from /3-hydroxy- 

 butyric acid. Thus, if the liver be perfused with blood containing this 

 substance, the blood which issues from the liver contains aceto-acetic 

 acid, and even minced liver will bring about the same transformation. 



Butyric acid is converted quantitatively by oxidation into /3-hydroxy- 

 butyric acid, whereas Magnus-Levy has pointed out that 100 grams 

 of Neutral Fat made up of tristearin, tripalmitin and triolein can yield 

 a maximum of only 36.2 grams of fl-hydroxybutyric acid. Hence 

 cream or Butter Fat, with its high content of butyrates, is a much more 

 dangerous source of "acetone bodies" than mutton-fat or bacon-fat 

 or butter-substitutes such as oleomargarine. This fact is illustrated 

 very strikingly in the intolerance which infants frequently display to 

 cream or butter, exhibiting decided symptoms of Acidosis when these 

 are administered in what, for other children, would be moderate 

 amounts. These infants not infrequently tolerate a higher fat, or even 

 olive oil, much better than they will tolerate cream or butter. 



The oxidation of the fats appears to take place in a series of similar 

 successive steps, the point of attack at each stage in the oxidation being 

 the ^-carbon atom, that is, the second carbon atom ia the hydrocarbon 

 chain, counting from the carboxyl-group. Thus Stearic Acid is con- 

 verted into Palmitic Acid in the following way: 



