5© 



Scientific Proceedings (36). 



32 (442) 



The depression of the ammonia destroying power of the liver 

 after thyroid-parathyroidectomy. 



By A. J. CARLSON and CLARA JACOBSON. 



[From the Hull Physiological Laboratory of the University of 



Chicago.^ 



1. The symptoms produced by intravenous injections of am- 

 monium carbonate and ammonium carbamate in dogs (Marfori) are 

 practically identical with the symptoms of thyroid-parathyroid- 

 ectomy in dogs, foxes and cats. The same is true of the typical 

 symptoms of poisoning on liberal protein diet in dogs with Eck 

 fistula or after ligation of the hepatic artery (Nencki, Pawlow, Sal- 

 eski, Rothberger, Winterberg, Hawk). After parathyroidectomy 

 in dogs there is an increase in the ammonia content of the blood 

 (MacCallum and Voegtlin). A high protein (meat) diet with its 

 attendant increase of ammonia in the portal blood accelerates and 

 intensifies the tetany in thyroid-parathroidectomized dogs (Munk, 

 Breisacher, Beebe). MacCallum and Voegtlin succeeded in obtain- 

 ing tetany in only three dogs when placed on starvation. We find 

 that in thyroid-parathyroidectomized cats the feeding of meat 

 appears to hasten the appearance of tremors and convulsions, and 

 that the symptoms are less severe and life is prolonged in starving 

 animals, but this point can be settled only after very extensive 

 experimentation because of the periodicity of the symptoms. The 

 foregoing facts taken altogether suggest that the tremors and con- 

 vulsions usually follozving thyroid-parathyroidectomy in carnivora 

 may be due to ammonia poisoning. 



2. The results of MacCallum and Voegtlin as regards the in- 

 creased ammonia content in dog's blood after parathyroidectomy 

 are confirmed on cats and foxes : 



100 c.c. blood of normal cats (5 experiments) contain 1. 54 mgr. ammonia. 



100 c.c. blood thyroidectomized cats (6 experiments) contain 2.52 " " 



100 c.c. blood normal foxes (4 experiments) contain 2.50 " " 



100 c.c. blood thyroidectomized foxes (4 experiments) contain.... 3.50 " " 



In no instance was the increase as great as that recorded by 

 MacCallum and Voegtlin for dogs. The ammonia content of 

 normal foxes is considerably higher than that of normal cats. 



