Ammonia Destroying Power of the Liver. 



5i 



3. The ammonia destroying power of the liver was determined 

 by perfusing the excised organ for 30 minutes at 40 0 C. with 

 mixture of blood (75 c.c.) and Ringer solution (225 c.c.) contain- 

 ing 20 mgr. ammonium carbonate per 100 c.c. 



Results. Ammonia destruction 



Livers of 1 5 normal cats 39 P er cent - 



Livers of 10 thyroid-parathyroidectomized cats 13 per cent. 



Depression 26 per cent. 



Livers of 3 normal foxes 44 per cent. 



Livers of 4 thyroid-parathyroidectomized foxes 14 per cent. 



Depression 30 per cent. 



The increase in ammonia in the blood after thyroid-para- 

 thyroidectomy is therefore due, at least in part, to depression of 

 the liver rather than to acidosis. The liver depression may be 

 due to changed conditions of the liver cells or to depressor sub- 

 stances in the blood. The diminished power of oxidation and 

 decreased rate of autolysis in the liver after thyroidectomy 

 (Stookey) point to the former alternative. These results support 

 Beebe's hypothesis of derangement of protein metabolism. 



4. In the case of the thyroid-parathyroidectomized animals 

 (foxes) that exhibit no typical symptoms (dyspnoea, salivation, 

 tremors, depression) there is no increase in the ammonia content 

 of the blood and no depression of the ammonia conversion power 

 of the liver. 



5. We are not prepared to say that the percentage of ammonia 

 increase in the blood after thyroid-parathyroidectomy is the pri- 

 mary factor in producing the symptoms. The increased ammonia 

 in the blood and the loss of calcium by the central nervous system 

 (MacCallum and Voegtlin) would probably work in the same direc- 

 tion as regards the production of tetany, but MacCallum's results 

 are flatly contradicted by Cooke. On the other hand, there is 

 probably an increase in the blood of other poisonous products of 

 protein catabolism besides ammonia, owing to the law of mass ac- 

 tion or to the impaired liver activity. 



6. The relation of the inorganic salts of the blood and of the 

 internal secretions of the parathyroids to the detoxication proc- 

 esses in the liver cells should be investigated. If the mere in- 

 crease of ammonia and other protein metabolites in the blood is the 

 cause of the apparent derangement of the magnesium (and perhaps 



