548 ABNORMALITIES IX METABOLISM 



of oxidation, so that tlie animal suffers from asphyxia exactly as if it 

 were deprived of air. In other Avords, the lack of alkalies in the 

 blood in acid intoxication checks the "internal respiration," as in- 

 tracellular gas exchange is called, by preventing the removal of COg 

 from the cells. The acids stimulate the respiratory center, which is 

 extremely sensitive to them, and the increased respiration tends to 

 reduce the acidity by getting rid of the CO,,-* but under the condi- 

 tions of the experiment this is not sufficient to prevent asphyxia. 



If the urine of such an animal is analyzed, it is found to contain 

 increased quantities of the four chief inorganic bases, Na, K, Ca, and 

 Mg (the last two apparently being derived from the bones), but in 

 addition to these it is found that the amount of ammonia in the urine 

 is decidedly increased. If instead of 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 intoxica- 

 tion. 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 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 protein metabolism is much greater 

 and more rapid than in herbivora, the ammonia available for neutral- 

 ization of acids is much- greater than in the latter, and hence the rela- 

 tive lack of susceptibility of carnivora to acid poisoning.-^ Accord- 

 ing to Landau,-*' the proteins of the blood also combine much of the 

 acid. Another factor, which is commonly overlooked, is the possible 

 accumulation of acids within the cells, which must modify greatly any 

 conclusions based upon studies of the blood and urine. It is witliin 

 the cells that the effects of acids must be manifested, and it is per- 

 fectly possible, and indeed almost certain, that we may have degrees 

 of acidity and alkalinity in the cells which are quite different from 

 those in the blood. 



As pointed out especially by Henderson,-"'^ the normal reaction of 

 the body is kept practically constant chietiy by : 1. The salts of COo 

 and H3PO4, existing in such proportions of carbonate, bicarbonate 

 and carbonic acid, or disodium- and monosodinm-hydrogen-phos- 



24 Sop Porpos, Wion. klin. Wooli.. 1011 (24). 1147. 



2r. Tliis lias Ih'oti iiiooly sliown liy Kppin},'6r (\\ii>ii. klin. Wooh.. 1006 (10). 111). 

 who found tliat administration of considorablo quantities of amino-acids (plyco- 

 ooll, alanine, aspartic acid) to rabbits proatly inoroasod tlieir resistance to acid 

 intoxication, presunialdy by yielding ammonia tlirougli normal steps of pro- 

 tein metabolism. 



2<! Arch. exp. Path. u. Pharm., 1000 (52), 271. 



2«a See Tlarvej' Society Lectures, 1014-15. 



