ACETONE BODIES. 821 



the body fat is consumed, and in several cases a certain relation has 

 been found between the fat consumed and the acetone bodies eliminated. 

 Certain investigators (GEELMUYDEN, SCHWARZ, WALDVOGEL) have 

 also observed an increase in the acetonuria on partaking of fatty food, 

 and FORSSNER l has indeed found a certain parallelism between the 

 acetone elimination and the fat taken up. For the present the fats are 

 considered as the most important source of the acetone bodies. 



The three acetone bodies occurring in the urine, as above stated, are 

 acetone, acetoacetic acid and /3-oxybutyric acid, and this last is considered 

 as the mother-substance of the other two. If /3-oxybutyric acid, 

 CHs.CHOH.CH2.COOH, is introduced into the animal body, it is burnt 

 if the quantity is not too great, while if in excess it passes into the urine 

 as acetoacetic acid, CHs.CO.CH2.COOH r This acid can also be burnt, 

 but if large quantities are introduced it appears in part in the urine and 

 readily splits into acetone, CHs.CO.CHs, and CO2. Acetone is in part 

 burnt in the animal body, but a part is eliminated by the kidneys and 

 especially by the lungs. We can imagine that the /3-oxybutyric acid is 

 a physiological metabolic product which normally is completely changed 

 into acetoacetic acid and acetone, and in diabetes and especially with 

 lack of carbohydrates is formed to an increased extent, or its combustion 

 made more difficult, so that in the first place acetone and acetoacetic 

 acid pass into the urine and in severe cases also /3-oxybutyric acid (acidosis) . 

 In this connection it must be borne in mind that, because of the previously- 

 mentioned (page 774) reversibility of the process, the direction may also 

 be reversed, that is acetoacetic acid can also be changed into /3-oxybutyric 

 acid in the animal body and this has been proven by perfusion of livers 

 (FRIEDMANN and MAASE) as well as in animals (DAKIN) and in diabetics 



(0. NEUBAUER) 2 . 



Since leucine in perfusion experiments with livers yields acetoacetic acid 

 (EMBDEN and ENGEL) and also, as BAER and BLUM S found, that leucine and iso- 

 valeric acid increased the /3-oxybutyric acid elimination in diabetics, it has been 

 accepted that a formation of /3-oxybutyric acid takes place from the leucine 

 with isovaleric acid as an intermediary product : 



(leucine CH 3 ) 2 CH.CH 2 .CH(NH 2 ).COOH-^(CH S ) 2 CH.CH 2 .COOH, isovaleric acid), 

 Valine (-amino-valeric acid (CH 3 ) 2 CH.CH(NH 2 ).COOH) is, on the contrary, 

 not an acetone former. 



1 Magnus-Levy, Arch. f. exp. Path. u. Pharm., 42; Geelmuyden, 1. c., and Norsk, 

 Magasin for Laegevidenskaben, 1900; see also Zeitschr. f. physiol. Chem., 41; Schwarz, 

 Deutsch. Arch. f. klin. Med., 1903; Waldvogel, Centralbl. f. inn. Med., 20; Forssner, 

 Skand. Arch. f. Physiol., 22 and 23. 



2 Friedmann and Maase, Bioch. Zeitschr., 27; Dakin, Journ. of biol. Chem., 8; 

 Neubauer, Maly's Jahresb., 40, 849. 



3 Arch. f. exp. Path. u. Pharm., 55 and 56; Embden and Engel, Hofmeister's 

 Beitrage, 11. 



