150 GLANDS IN HEALTH AND DISEASE 



result that an excess of glucose appears in the 

 blood, and finally in the urine, giving rise to the 

 sugar disease, diabetes. 



It would seem as if the thyroid, and particularly 

 the adrenals, accelerate the conversion of glycogen 

 to glucose, and that the pancreas, and perhaps to 

 some extent the parathyroid, retard such a conver- 

 sion. Eppinger and his 1 colleagues reached this 

 conclusion from studies of the effect on protein 

 metabolism of injecting adrenaline. They found 

 that this increased protein metabolism (the amount 

 of protein digested and utilized) was the same as 

 that seen in hyperthyroidism and the opposite of 

 that produced by the removal of the thyroid gland. 

 On the other hand, the pancreas seems to prevent 

 the formation of an excessive quantity of sugar, for 

 we see that such an excessive quantity is produced 

 when the pancreas is removed. As for the para- 

 thyroid, the general feeling that it tends to neutral- 

 ize thyroid activity has made some investigators 

 class it on the side of the pancreas. These actions 

 are shown in Fig. 2. 



Fig. 1 shows that the pancreas, thyroid and adre- 

 nals, in addition to influencing sugar metabolism 

 in the liver, influence the activity of one another. 

 Thus the thyroid and adrenals excite one another 

 to activity, whereas the thyroid and the pancreas, 

 and the adrenals and pancreas, inhibit one an- 

 other's activity. 



