634 LEWELLYS F. BARKER 



of Paton, and of others, who have found guanidin accumulations in the 

 body in tetajiy be confirmed, I would suggest that, in autopsies on tetany 

 patients, tests be made to see whether or not arginase is absent. Arginin 

 has been found in the spleen (Gulewitsch) and it might be well to test the 

 spleen and other organs for the presence or absence of arginase and sim- 

 ilar guanidin transforming ferments; and, since the presence of healthy 

 parathyroids prevents tetany, I would further suggest that the parathyroid 

 glands themselves be examined for arginase, for it might very well be that 

 these glands are the source of this ferment, and perhaps of other important 

 catalytic agents. 



Metabolism of Nucleins and Purins in Tetany 



In connection with the metabolism of nucleins and purins, attention 

 may be drawn to three sets of substances that have this source, (1) xanthin 

 and its derivatives (guanin and caff em), (2) inosinic acid, and (3) phos- 

 phoric acid. 



Xanthin and Its Derivatives. It has long been known that xanthin 

 and its substitution products belong to a group of convulsive toxins, which, 

 acting upon the nerve centers rather than upon the peripheral nerves, cause 

 muscular twitchings and rhythmical contractions, followed by paralysis. 

 Berkeley and Bcehe, thinking that these substances might impinge upon 

 the same mechanism as the hypothetical toxin of tetany, made some experi- 

 ments in the treatment of xanthin poisoning, in which they made use of 

 remedies that are known to ameliorate the symptoms of tetany. They 

 found that the toxic effects of intravenously injected xanthin can be very 

 promptly relieved by the administration of salts of calcium and of stron- 

 tium, though the betterment is not quite so prompt as is seen in the treat- 

 ment of the symptoms of tetany by the same salts. Though Berkeley and 

 Beebe did not suggest that tetany is due to poisoning by ammonia or by 

 xanthin, these authors thought it probable that the poisoning in tetany may 

 be due to some chemical substance of metabolic origin that acts in a way 

 similar to that of xanthin. They inclined also to the belief that the para- 

 thyroid glands are concerned chiefly in furnishing enzymes that are of 

 prime importance for the intermediary metabolism of nitrogen. 



Xanthin, guanin, and caffein all contain a guanidin group, which could 

 possibly be brought into relation with a guanidin intoxication of the body 

 (vide supra). Guanidin of this source would have to be attributed to a 

 disturbance of pnrin metabolism, rather than to an anomaly in the metab- 

 olism of proteins, Xanthin is converted into uric acid by means' of a, 

 ferment known as xanthin oxydase. In human beings this ferment has. 

 been found in only one organ, namely, the liver. In animals it has been 

 found in other organs also, especially in the spleen. Guanin is derived also 



