264 Studies in Metabolism. I 
thyroidectomized animals acts upon the muscle of frogs in the 
same way as do dilute solutions of guanidine (23). The admin- 
istration of the salts of guanidine to animals induces symptoms 
almost identical with those of tetania parathyreopriva (7). The 
above evidence strengthens the view that a function of the para- 
thyroids is the regulation of the metabolism of guanidine in the 
body and that the guanidine thus produced controls the tone of 
the muscle as mentioned by Paton and Findlay (24). 
The results of the present investigation show that the hypo- 
glycemia which is manifested in tetania parathyreopriva, as 
shown by Underhill and Blatherwick (19), can also be produced 
by the injection of guanidine hydrochloride. The hypoglycemia 
manifested after parathyroidectomy may be a secondary mani- 
festation of guanidine poisoning. 
The hyperglycemia induced several hours after administration 
of the drug, especially after the second and third injection, may 
be considered to be due to the disturbance of respiration since it 
is well known that dyspnea induces an increase in the sugar . 
content of the blood. 
CONCLUSIONS. 
The administration of guanidine hydrochloride into rabbits 
induces symptoms which are almost identical with those of tetania 
parathyreopriva. At the same time hypoglycemia is induced 
which also occurs after the removal of the parathyroid. There- 
fore the hypoglycemia resulting from the lack of parathyroid 
may be due to the action of guanidine which is increased in the 
blood under these conditions. | 
The hypoglycemia induced by injection of guanidine is not due 
to the diminution of total solids or to the dilution of the blood. 
The author acknowledges his indebtedness to Professor F. P. 
Underhill for suggestions and advice in carrying out this work. 
BIBLIOGRAPHY. 
1. Paton, D. N., and Findlay, L., Quari. J. Exp. Physiol., 1916, x, 203. 
2. Joseph, D. R., and Meltzer, S. J., J. Pharm. and Exp. Therap., 1910-11, 
i, 361. 
3. Voegtlin, C., and MacCallum, W. G., J. Pharm. and Exp. Therap., 
1910-11, ii, 439. 
