S. Kuriyama 201 
As the diastase content of the blood serum of normal rabbits, 
Wohlgemuth and Benzur'® obtained the value of D.n = 62.5, 
which sometimes increased to 100 or 150. In my normal rab- 
bits, the blood serum always showed the value of Dn = 62.5. 
After thyroid feeding, the diastase content of the blood serum 
remained about the same. As to the diastase content of the 
liver, the animal species seem to show some noteworthy differ- 
ence. In rabbits it is said to vary between D,n = 5 and 12.5 
(Wohlgemuth and Benzur'®), while in rats De is as high as 80 
(meat feeding) or 160 to 320 (bread or lard feeding) (Hirata**). 
In my own experiments, the diastase content of the normal rat 
liver was ie = 156 to 250. This accords well with Hirata’s 
results. In thyroid-fed rats, the value was about the same. As 
far as the diastase content of the blood serum and the liver is 
concerned, the decrease of the glycogen content of the liver in 
experimental hyperthyroidism does not seem to be due to an 
increased glycogenolytic power of the liver or blood. 
The diastase content, however, is always determined on the 
dead material. The diastatic power of such substances may 
not be identical with that in the living condition. Compar- 
ing the diastatic efficiency and average glycogen content in the 
different tissues and organs, MacLean* reported that the dias- 
tatic power and the glycogen content do not necessarily run paral- 
lel and sometimes an organ containing merely a trace of glycogen, 
e.g., the lung, shows a more marked amylolytic power than a 
. glycogen-rich organ, such as the liver. Moreover, a long list of 
substances, which accelerate or inhibit the activity of diastase, 
has been reported. A small amount of such substances within 
the living cells may markedly affect the activity of this enzyme. 
It is a well known fact that a marked increase of protein and fat 
metabolism exists in hyperthyroidism. The nitrogenous con- 
stituents of the urine are usually increased. Bock** reported an 
increase of amino-acid nitrogen of the blood in a case of hyper- 
thyroidism (9.58 mg. amino-acid N in 100 cc. of blood; the nor- 
2 Hirata, G., Biochem. Z., 1910, xxvii, 385. 
33 MacLean, H., Biochem, J., 1909, iv, 467. 
eS pock, J. Ci, J. Biol, Chem. 1917, xxix, 191; 
