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THE DUCTLESS GLANDS 



A very interesting contribution to the subject of the internal 

 secretion of the adrenal bodies has been made by Cannon and 

 de la Paz. They point out that, according to the researches of 

 Dreyer, Asher, and Tscheboksaroff, the adrenal secretion is 

 under control of the thoracicolumbar autonomic (sympathetic) 

 system. They further call attention to the fact that the 

 phenomena of a major emotional exhibition in an animal 

 indicate the dominance of sympathetic impulses. When, for ex- 

 ample, a cat becomes frightened, the pupils dilate, the stomach 

 and intestines are inhibited, the heart beats rapidly, the hairs 

 of the back and tail stand erect all signs of nervous discharges 

 along sympathetic paths. The authors put to the test the sug- 

 gestion that the adrenal glands share in the widespread subjuga- 

 tion of the viscera by sympathetic control. 



The inhibition of contraction in strips of longitudinal 

 intestinal muscle was used as a physiological test. 1 Blood 

 was obtained from a cat when quiet, and again after the animal 

 was excited by the presence of a barking dog. After an initial 

 shortening the strip contracted rhythmically in blood from a 

 quiet animal. In no instance did such blood produce inhibition. 

 On the other hand, blood taken from animals after the emo- 

 tional disturbance showed more or less promptly the typical 

 relaxing effect. The effect was obtained in blood from the 

 inferior vena cava near the liver. The authors believe that 

 the effect was due to secretion on the part of the adrenal glands, 

 and they offer a further suggestion that the persistence of the 

 emotional state after the exciting object has disappeared may be 

 in part due to an autogenous continuance of adrenal secretion. 



A number of histological observations have been recorded, 

 which have been interpreted as pointing to an active secretion 

 on the part of the adrenal medulla. Manasse described brown 

 masses in the bloodvessels of the adrenal body, and small 

 highly refractive, colourless granules in the adrenal vein of the 



1 The authors discuss the various methods of testing for adrenin. The 

 frog-eye method of Meltzer and Ehrmann did not give sufficiently striking 

 results. Strips of ox artery, employed by Meyer, though highly sensitive, 

 did not seem serviceable because of Schlayer's discovery that the method 

 is less efficient when used with foreign blood. The uterus method requires 

 several hours. So they finally decided upon the longitudinal intestinal 

 muscle. One of the chief advantages of this preparation is that it responds 

 by relaxing. This is very important, for other substances in blood than 

 adrenin e.g., CO 8 will cause smooth muscle to contract, whereas known 

 substances evoking relaxation of smooth muscle are few and unusual in blood. 



