534 SUTHERLAND SIMPSON 



Berkeley and Beebe (a) prepared an extract from beef parathyroids 

 from which /hey succeeded in separating a nucleoprotein that appeared to 

 them to have curative properties when administered to animals suffering 

 from parathyroidectomy. 



This active nucleoprotein was administered to thirty-two animals with 

 typical symptoms of tetany, and it was effective in ninety-five per cent of 

 these. Incidentally, it may be mentioned, that they found no iodin in 

 the analysis of any of the parathyroids examined by them, human, dog, or 

 ox. 



Other investigators have been unable to find curative properties in 

 parathyroid preparations. Edmunds fed large quantities to an animal in 

 tetany without any result. On the other hand, Stenvers (1917) describes 

 a case in man with violent tetany (accidental thyroparathyroidectomy), in 

 which the administration of fresh horse parathyroid kept the patient nor- 

 mal until three parathyroids obtained in a goiter operation were implanted. 

 The man was restored to perfect health. 



The physiological effects of the intravenous injection of the extract 

 have not been extensively investigated. It is reported to give a fall in 

 blood pressure, as do the extracts of most animal tissues, but no specific 

 action can be assigned to it, despite the fact that such action has frequently 

 been claimed. 



The Relation of the Parathyroid Glands to Metabolism. Exciting 

 Cause of Symptoms. With regard to the origin of the symptoms, already 

 described, which usually appear within a comparatively short time after 

 the parathyroids have been removed, little is definitely known. Two main 

 hypotheses have been advanced by physiologists to explain the effects. 

 These may be designated the calcium deficiency theory and the toxin 

 theory. 



RELATION OF THE PARATHYROIDS TO CALCIUM METABOLISM. The 

 view that the nervous and muscular disturbances which follow parathyroid 

 extirpation are due to a deficiency of calcium in the nervous system has 

 been advocated mainly by MacCallum and his pupils, who have brought 

 forward a considerable amount of evidence in its favor. 



Studies on Calcium Phat*macology. In a paper published by Mac- 

 Gallum and Voegtlin in 1909 the literature is reviewed up to that date 

 and the results of their own contributions to the subject recorded. Gregor 

 in 1900 first suggested that the diet might have something to do with 

 the nervous and muscular symptoms in infantile tetany. In the follow- 

 ing year Sabbatani, as the result of animal experimentation, stated that 

 calcium salts are antagonistic in their action to sodium citrate. The ex- 

 citability of the motor cortex is diminished, both to mechanical and elec- 

 trical stimulation, by the direct application to it of isotonic solutions of 

 calcium chloride. The action is very rapid; immediately after its applica- 

 tion a much stronger stimulus is required to produce muscular contrac- 



