452 METABOLIC ABNORMALITIES, AUTOINTOXICATION 



a rabbit a carnivorous animal, such as a dog, is given acids, it 

 will be found relatively insusceptible, so that great quantities 

 can be given without causing acid intoxication. Examination 

 of the urine of such a dog will show that the elimination of 

 ammonia is increased much more than it is in the herbivora, 

 while the inorganic alkalies are relatively increased but little. 

 From this it is deduced that in acid intoxication part of the 

 nitrogen that normally goes to form urea becomes, while in 

 the antecedent form of ammonia, combined with part of the 

 acid that has entered the blood. In this way much of the 

 neutralization of the acids is accomplished by ammonia, and 

 the inorganic alkalies of the blood are spared. As in carnivora 

 the amount of proteid metabolism is much greater and more 

 rapid than in herbivora, the ammonia available for neutraliza- 

 tion of acids is much greater than in the latter, and hence the 

 relative lack of susceptibility of carnivora to acid poisoning. 1 

 According to Landau, 2 the proteids of the blood also combine 

 much of the acid probably one-half of it and perhaps more. 



DIABETIC COMA 3 



In man, poisoning with inorganic poisons, as in the experi- 

 ments cited above, is a rare occurrence, but not infrequently 

 acid intoxication results from the presence of undue quantities 

 of organic acids produced in metabolism. The most striking 

 example of this is the coma of diabetes, in which the asphyxia 

 without cyanosis, dependent upon failure of the blood to carry 

 CO 2 , is strikingly similar to that observed in experimental ani- 

 mals poisoned with acids. In diabetic coma the acid intoxica- 

 tion is due chiefly to the accumulation in the blood of large 

 quantities of ft-oxybutyric add. Associated with it, in smaller 

 quantities, are usually found diacetic (aceto-acetic) acid and 

 acetone, which are chemically so closely related that it is gener- 

 ally considered that they are derived from the oxybutyric acid, 

 as follows: 



/9-oxybutyric acid is 



CH 3 CHOH CH 2 COOH, 



and by oxidation this readily forms 



CH 3 CO CH 2 COOH, 



lr This has been nicely shown by Eppinger (Wien. klin. Woch., 1906 (19), 

 111), who found that administration of considerable quantities of ammo-acids 

 (glycocoll, alanin, aspartic acid) to rabbits greatly increased their resistance to 

 acid intoxication, presumably by yielding ammonia through the normal steps 

 of proteid metabolism. 



2 Arch. exp. Path. u. Pharm., 1900 (52), 271. 



3 See also v. Noorden's " Diabetes Mellitus, " 1905, New York. 



