The Endocrine Glands - 407 



heart action becomes stronger and quicker; 

 but the digestive tract becomes quiescent. 

 The skin pales, the pupils dilate, and the 

 hair erects. Moreover, adrenalin produces a 

 marked effect upon the arteries. The arteries 

 supplying the viscera and skin become con- 

 stricted — which shunts most of the circula- 

 tion into the lungs, muscles, and brain. The 

 spleen contracts, augmenting the total quan- 

 tity of circulating blood, and the liver draws 

 upon its glycogen reserves to mobilize addi- 

 tional blood sugar. The coagulation reactions 

 of the blood are also speeded up consider- 

 ably. 



In sum total, adrenalin simulates a gener- 

 alized excitation of the whole sympathetic 

 nervous system (p. 465). The body displays a 

 similar picture under stress of fear and anger, 

 which likewise calls forth a widespread hyper- 

 activity of the sympathetic nerves. These ob- 

 servations form a basis for the emergency 

 theory of adrenal function. According to 

 this view, the sudden release of extra adren- 

 alin in times of stress is instrumental in 

 transforming the body into a more effective 

 "fighting machine." 



The Adrenal Cortex. An absence of the 

 cortex accounts for the prostration and early 

 death that follows a total extirpation of the 

 adrenal glands; adrenalectomized animals 

 remain alive and free of drastic symptoms if 

 about one fifth of the cortical tissue remains 

 intact — irrespective of the presence or ab- 

 sence of any medullary tissue. 



The symptoms of adrenal cortical insuffi- 

 ciency, which culminate in death, are nu- 

 merous and obscure. Apparently there is a 

 generalized derangement of carbohydrate 

 metabolism. The tissues display an impaired 

 capacity lor deriving glucose from protein 

 sources, and the blood glucose is apt to fall 

 to a dangerous level. The osmotic charac- 

 teristics of the blood are also seriously al- 

 tered. The kidneys fail to reabsorb adequate 

 quantities of inorganic salts, especially NaCl. 

 Under these circumstances of lowered os- 

 motic pressure, fluid tends to escape too 

 rapidly from the capillaries, the blood plasma 



faiis to maintain its normal volume, the 

 blood pressure falls drastically, and the ani- 

 mal goes into a state of "shock." During a 

 protracted cortical insufficiency, the sex func- 

 tions also fail — although this failure prob- 

 ably represents an indirect effect resulting 

 from the metabolic derangement that ac- 

 companies the deficiency. In males the semi- 

 niferous tubules degenerate; and in females, 

 the Graafian follicles stop developing — or if 

 pregnancy has started, abortion follows. 

 Moreover, mothers with recently delivered 

 olfspring fail in the secretion of milk. 



The first life-sustaining extract of the 

 adrenal cortex, obtained in 1930, was named 

 cortin. Subsequently many efforts have been 

 made to isolate, purify, and identify the 

 individual active components of the extract; 

 and these efforts have been fairly successful. 

 In fact, some 20 compounds have been ob- 

 tained, among which Cortisol (C 2 iH 30 O r ,), 

 deoxycorticosterone (C 21 H S0 O 3 ), and aldos- 

 terone (C 2 ,H 2S O r ,) are perhaps the most im- 

 portant. All the isolated substances are ster- 

 oid compounds, and all bear a close chemical 

 relationship to the hormones produced by 

 the testes and ovaries. Probably some of these 

 compounds are merely derivatives of the hor- 

 mones naturally present in the intact cortex. 



In 1948 one of the adrenocortical hor- 

 mones, namely Cortisol was synthesized 

 artificially, and this compound relieves many 

 of the symptoms of adrenocortical insuffi- 

 ciency. It also possesses astonishing alleviative 

 values when used in the treatment of rheu- 

 matoid arthritis and certain other diseases 

 in man. However, Cortisol must be admin- 

 istered with caution because of its great 

 potency and many side effects. 



Recently aldosterone has also been isolated 

 and synthesized artificially. Aldosterone is 

 very effective in regulating the osmotic bal- 

 ance between the blood and the tissues and 

 seems to provide a valuable treatment for 

 cases of surgical, or traumatic shock. 



There are still a number of unsolved prob- 

 lems as to the functions of the adrenal cor- 

 tex. The total potency of cortin (the un- 



