596 SAMUEL H. HTJRWITZ 



Splenectomy. The use of splenectomy as a mode of treatment in 

 diseases of the blood is now limited for the most part to the so-called 

 primary anemias, to Banti's disease, and to hemolytic icterus. In con- 

 sidering therefore the influence of splenectomy on metabolism, attention 

 will be directed only to these conditions. 



Experimental Observations. The effect of removing the spleen 

 in normal animals on the elimination more especially of nitrogen and 

 iron is of great interest because of the possible relationship existing be- 

 tween the quantity of these substances excreted and the repair of the 

 anemia which is known to follow splenectomy. Some of the earlier 

 work on normal animals is reviewed by Pearce and his co-workers. Care- 

 ful control of the nitrogen intake and the long periods of observation 

 give to the experiments of Pearce and his associates greater value than 

 is possessed by the work prior to theirs. 



The nitrogen metabolism after splenectomy was followed in four 

 animals for periods varying from three days to three months. In one of 

 these a positive nitrogen balance of 0.45 gram before operation remained 

 practically unchanged three days after splenectomy. Essentially the same 

 results were obtained in a second animal eight weeks after operation, 

 while in two other instances a moderate retention of nitrogen occurred; 

 a positive balance of 0.48 gram per day in one of these experiments 

 became slightly negative ten days after splen-ectomy, and definitely posi- 

 tive again three months after operation when the animal was retaining 

 1.10 grams of nitrogen daily. Such experimental evidence does not sup- 

 port the view that the spleen markedly influences nitrogen metabolism. 

 The moderate retention of nitrogen noted during certain periods after 

 splenectomy is probably due to the utilization of nitrogen for the repair 

 of the anemia which usually follows removal of the spleen. 



Whether the spleen plays any essential part in iron metabolism is 

 a question raised by the work of Grossenbacher and of Zimmermann. They 

 studied the iron elimination of four puppies with and without splenectomy, 

 and found that there was a marked increase in the output of iron follow- 

 ing removal of the spleen, an increase which persisted at times for ten 

 months. From these experiments, they concluded that the spleen is an 

 important organ in intermediary metabolism, enabling the body to con- 

 serve and reutilize its iron. 



This view, however, is not supported by the careful experiments of 

 Pearce and his associates. Austin and Pearce studied the metabolism of 

 iron in dogs both before and from four days to twenty months after 

 splenectomy. Only three out of the five animals showed an increased 

 iron elimination after operation, and then only during the first two 

 weeks, this being absent one month, nine months, and twenty months after 

 splenectomy. In a later series of experiments, Goldschmidt and 

 Pearce noted in one out of four splenectomized dogs an increased elimina- 



