292 CORTEX 



of adrenal extracts may also be vitiated by the presence of 

 choline and its esters since the pressor effect of epinephrine 

 is easily antagonized by small amounts of these substances. 



VITAMINS 



The adrenals contain appreciable quantities of vitamins 

 A, B, C, G, and probably other vitamins in lesser concentra- 

 tions. The idea of the existence of an intimate relationship 

 between the adrenal cortex and vitamins A, B, (Bi), C, and 

 G (B 2 ) has received much attention in recent years. This 

 supposed relationship has been based upon: 1) the high con- 

 centrations of the vitamins (particularly A and C) occurring 

 in the adrenal; 2) the changes occurring in the adrenal during 

 avitaminosis (atrophy in avitaminosis A; hypertrophy in 

 avitaminosis B and C); 3) the increase in susceptibility to 

 infectious disease in avitaminosis and in adrenal insufficiency; 

 4) the similarity between certain of the clinical manifestations 

 of avitaminosis and of adrenal insufficiency; 5) the alleged 

 ameliorating effects of cortical extracts in avitaminosis B and 

 C ; 6) the similarity between certain of the chemical properties 

 of the adrenal cortical hormone and vitamin G (B 2 ). 247 



Vitamin A. The high concentration of carotene (pro- 

 vitamin A) in the cortex may be attributed to the high lipid 

 content of the gland. Other lipoidal tissues, such as the corpus 

 luteum also contain equally high concentrations of pro-vitamin 

 A, and we may therefore consider the existence of pro-vitamin 

 A in the adrenal to be due to the laws of distribution based on 

 simple solubility relationships. The adrenal atrophy occur- 

 ring during avitaminosis A may be considered as part of a 

 general reaction to the lack of a vital factor necessary for the 

 well-being of many organs and tissues. There seems no 

 reason, therefore, to assume the existence of an intimate rela- 

 tionship between vitamin A and the adrenal cortex. 456 



Vitamin B (J5i). Pico-Estrada 606 demonstrated the in- 

 creased susceptibility of adrenalectomized rats to avitaminosis 



