RELATION TO OTHER ENDOCRINES 223 



insufficiency are due to parathyroid overactivity which causes 

 a disturbance in the calcium metabolism, because changes in 

 calcification of the dentin of rat's teeth after adrenalectomy 

 resembled that caused by administration of parathyroid hor- 

 mone. The muscular twitchings, spasms, and tetanic convul- 

 sions often occurring in animals in insufficiency may be due to 

 a disturbance in calcium metabolism. Although Rogoff and 

 Stewart 630 reported a decided hypercalcemia in most of their 

 animals, other observers have noted no great change in the 

 blood calcium to indicate any significant alteration in the 

 calcium metabolism. However, it must be remembered that 

 changes in other ions particularly phosphate, which is also 

 increased, will act to modify the state and hence the physio- 

 logical effectiveness of the calcium. Hence too great empha- 

 sis should not be placed upon the total calcium concentration 

 as determined by analysis. There is, however, no good evi- 

 dence to show that the parathyroid glands are stimulated to 

 over-activity by adrenal insufficiency and one cannot accept 

 the suggestion that the changes in the alimentary tract ob- 

 served in adrenalectomized animals are due to an excessive 

 secretion of the parathyroid hormone. 



In the adreno-genital and Cushing's syndrome (cf. Chap- 

 ter XXIII) due to tumors of the adrenals and pituitary, one 

 observes a softening of the bones due to decalcification. This 

 evidence of a possible parathyroid disturbance may be ascribed 

 to changes in the ovaries or pituitary, which are known to exert 

 an influence on the calcium metabolism. Both the pituitary 

 and the ovaries are affected in these conditions and hence it 

 would seem more logical to attribute the observed effects to 

 the action of these glands on parathyroid activity rather than 

 to assume any control by the adrenals over the parathyroid. 

 As in the case of the thyroid, therefore, we must conclude that 

 there exists no valid evidence to indicate any intimate adrenal- 

 parathyroid interrelationship. 



