PARS GLANDULARIS AND METABOLISM 



ably is slight and unimportant.) Without pituitary secre- 

 tion either from the intact gland or from administered ex- 

 tract, the adrenal cortex rapidly diminishes in size and per- 

 forms its usual functions only imperfectly. The principal 

 morphological evidences of atrophy are in the outer part of 

 the thickest layer of the cortex, the zona fasciculata, al- 

 though the zona glomerulosa also is affected. There is a 

 striking loss of lipoids. The administration of a suitable an- 

 terior pituitary extract not only restores the lipoids lost but 

 may increase their concentration in association with hyper- 

 trophy and hyperplasia of cortical cells. In this way an ex- 

 tract may cause cortical enlargement in hypophysectomized 

 rats, so that the adrenal glands are larger than any ever en- 

 countered in normal rats receiving no treatment. 



The X-zone of the innermost part of the cortex of young 

 female mice or of castrated males seems also to depend upon 

 an anterior pituitary hormone for its development (Deanes- 



ly). 



The physiological interrelationships of the adrenal cortex 

 and the anterior pituitary are important and numerous; un- 

 fortunately, however, they have been explored only imper- 

 fectly. Compensatory adrenal hypertrophy requires adrenal 

 cortical stimulating hormone. This hormone probably is se- 

 creted at an increased rate if there is cortical deficiency, 

 whereas a change in the opposite direction takes place if 

 abnormally large amounts of adrenal cortical hormone(s) are 

 present in the body-fluids. Some of the most important cor- 

 relations appear to affect the metabolism of carbohydrates 

 and fats and are mentioned in later discussion. 



The pars glandularis appears to be the principal division 

 of the pituitary body important in the metabolism of car- 

 bohydrates. The substance or substances responsible for par- 

 ticipation in this important phase of metabolism has been 

 detected in anterior pituitary extracts which, for the most 

 part, are quite crude. The isolation of these substances must 



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