222 CORTEX 



thyroidectomy and feeding of desiccated thyroid substance on 

 the epinephrine content of the adrenals has given conflicting 

 results. 294 The results following injections of thyroid extracts 

 have been equally inconclusive. The older experiments in 

 which it was claimed that such injections sensitized the organs 

 innervated by the sympathetic nervous system to a subsequent 

 injection of epinephrine have been shown to be non-specific 

 reactions to foreign protein. Thyroxin induces no such 

 sensitization. 639 



Koehlsche and Kendall 364 have recently studied the effect 

 of administering adrenal cortical extracts on the nitrogen excre- 

 tion of dogs after injection of thyroxin. They consider their re- 

 sults as indicating the existence of a thyroid-adrenal interrelation. 



PARATHYROIDS 



Injection of epinephrine modifies the calcium content of the 

 blood and attempts have, therefore been made to link para- 

 thyroid and adrenal medullary activities. The assumption of 

 such a relationship has not, however, been substantiated. 

 With the transferral of emphasis from the medulla to the cor- 

 tex as the important part of the adrenals, attempts have been 

 made to demonstrate an intimate relation between the adrenal 

 cortex and the parathyroid glands. Thus the fact that both 

 the administration of parathyroid extracts and adrenalectomy 

 increase the cholesterol content of the blood suggested that 

 parathyroid hyperactivity depresses the activity of the cortex. 

 The hyperplasia of the adrenals noted in a case of osteitis 

 fibrosa suggested, on the other hand, that over-activity of the 

 parathyroids stimulates the adrenals. The relative ease with 

 which the cholesterol content of the blood can be affected and 

 the many factors which cause an hypertrophy of the adrenals 

 renders the evidence just cited for the existence of an adrenal- 

 parathyroid relationship exceedingly flimsy. 



Rogoff 624 has suggested that some of the symptoms of adrenal 



