548 SUTHERLAND SIMPSON 



circulation. For example, both produce an interference with vagocardia,c 

 inhibition, which is removed by salts of calcium. 



Watanake (e) (/) supports Paton's guanidin theory of parathyroid 

 tetany. By the administration of guanidin hydrochloride to rabbits he was 

 able to produce hypoglycemia, which also occurs after parathyroidectomy. 



Koch (d) (1918), in an elaborate article, discusses the physiology of 

 the parathyroid glands. He claims to have put forward the guanidin theory 

 in 1913, and agrees with Paton's views. The precursor of guanidin may 



Fig. 9. Tetanus-like response to single stimulus of frog's muscle immersed in 

 serum from blood of parathyroidectomized dog. Time in 1/10 sec. (Wishart. ) 



he cyanamid. Calcium alleviates tetany because it decreases the permea- 

 bility of the body cells, which allows them to take up guanidin. In an- 

 other communication he makes a further contribution to the subject. 



Henderson estimated the guanidin in muscle, and found that there 

 was a fall in the total and in the free guanidin after parathyroidectomy, 

 and a rise in creatin. This may indicate either a liberation of guanidin 

 from the muscle, or a failure in the power of the muscle to take it up from 

 the circulation. Either hypothesis will account for the fact that guanidin 

 is increased in the blood. 



Sharpe estimated the guanidin in the feces of normal children and 

 those suffering from idiopathic tetany, and found that in the latter it was 

 greatly increased. 



