ON eck's fistula 9 



In the arterial blood of dogs fed on flesh the amnnonia content is 

 about 1*5 mg. per icxD cc. It is very constant. 



In the portal blood, under the same conditions, from 3 to 4 times as 

 much ammonia is present, being, however, variable in amount. In the 

 blood of the branches of the portal vein, coming from the stomach, 

 pancreas and intestines, the percentage of ammonia is still higher. 



In the mucosa of the stomach, the brain and lungs a very high 

 ammonia percentage exists. 



During fasting, the percentage of ammonia in all the above situations 

 falls markedly (o'4 mg. per 100 cc. in arterial blood). 



Concerning the source of the ammonia in the portal blood a large 

 part of it comes from glandular activity, for it appears in the portal blood 

 when a fasting dog is merely tempted with savoury food ("sham 

 feeding.") When food is ingested, still more ammonia appears. Its 

 source is therefore double — from the active glands and from the food. 

 Ammonia is produced elsewhere in the body from the katabolism of 

 proteid food stuffs. 



The above observers have also examined the ammonia content of the 

 blood and various organs in Eck's fistula dogs, and have come to the 

 following conclusions. 



In the blood and urine there may or may not be an increased amount 

 of ammonia, but in dogs which have died of the above symptoms a large 

 excess of ammonia is always found in the brain.* Salaskin sums up the 

 main conclusions of this part of the investigations of the St. Petersburg 

 workers in the following manner. 



After the establishment of the fistula, when the dog is on a flesh diet, 

 the ammonia which is produced by the activity of the gastro-intestinal 

 glands and from the food is carried by the portal blood directly to the 

 systemic circulation. Under normal conditions by far the greater propor- 

 tion of this ammonia will become converted into urea in the liver. In the 

 circulation the ammonia produced in the tissues by katabolic processes 

 is added to it. A part of this excess of ammonia in the blood is filtered 

 through the kidneys into the urine, some passes via the hepatic artery to 

 the liver, and is converted into urea f and the remaining excess becomes 

 stored away in some unknown combination in the organs, especially in 



* A table giving all the details of these observations will be found in Salaskin's paper, 

 t Some may also be converted in urea elsewhere than in the liver. 



(273) T 



